Switching method, base station and terminal

ABSTRACT

Provided are a switching method, a base station and a terminal. The method includes that: a base station configures a switching message for a narrow-bandwidth receiving mode, the switching message including time when a terminal is indicated to enter the narrow-bandwidth receiving mode and a position of a narrow bandwidth on a frequency band when the narrow-bandwidth receiving mode is entered; and the switching message is sent to the terminal to indicate the terminal to switch to the narrow bandwidth specified in the switching message for information reception, the narrow bandwidth being smaller than a system bandwidth. With adoption of the embodiments, the terminal may receive a signal on the narrow bandwidth, and reduction in power consumption of the terminal is facilitated.

CROSS-REFERENCE TO RELATED APPLICATIONS

The present application is the U.S. national phase of PCT ApplicationNo. PCT/CN2017/095246 filed on Jul. 31, 2017 which claims a priority toChinese Patent Application No. PCT/CN2017/070481 filed in China on Jan.6, 2017, the entire disclosures of which are incorporated herein byreference.

TECHNICAL FIELD

The disclosure relates to the technical field of communications, andparticularly to a switching method, a base station and a terminal.

BACKGROUND

In a Long Term Evolution (LTE) system, a terminal receives downlinksignals in the whole system bandwidth. Here, the downlink signalsinclude Physical Downlink Control Channels (PDCCHs) and downlink commonreference signals such as Cell-specific Reference Signals (CRSs) andChannel State Information Reference Signals (CSI-RSs). System bandwidthssupported by an LTE system include 1.4 MHz, 3 MHz, 5 MHz, 10 MHz, 15 MHzand 20 MHz. Here, 20 MHz and 10 MHz are system bandwidths that aretypical and applied more often, and correspond to 100 Physical ResourceBlocks (PRBs) and 50 PRBs respectively for downlink channels.

In an existing LTE system, a terminal usually does not know about aformat of information being transmitted by Downlink Control Information(DCI) or know about a position where the information required by itselfis located. However, the terminal knows about information it expects.The terminal may perform Cyclic Redundancy Check (CRC) on differentexpected information and Control Channel Element (CCE) information in aPDCCH by corresponding Radio Network Temporary Identities (RNTIs), andif CRC succeeds, the terminal can know that the information is neededfor itself, thereby obtaining a corresponding DCI format and amodulation manner and further parsing the content of the DCI. This iscalled a blind detection. The terminal may keep performing blinddetection on the PDCCH in the whole downlink system bandwidth, which maybring high power consumption to the terminal. Particularly in a5-Generation (5G) system and a subsequent mobile communication systemwith a large system bandwidth, a bandwidth of a carrier may be largeand, for example, may reach 200 MHz. Therefore, if a terminal stillreceives a PDCCH on the whole bandwidth as in an LTE system, i.e., a4-Generation (4G) system, power consumption of the terminal may be veryhigh.

SUMMARY

Embodiments of the disclosure provide a switching method, a base stationand a terminal, to enable the terminal to receive a signal on a narrowbandwidth and facilitate reduction in power consumption of the terminal.

A first aspect of the embodiments of the disclosure provides a switchingmethod, which may include the following operations.

A base station configures a switching message for a narrow-bandwidthreceiving mode, the switching message including time when a terminal isindicated to enter the narrow-bandwidth receiving mode and a position ofa narrow bandwidth on a frequency band when the narrow-bandwidthreceiving mode is entered.

The switching message may be sent to the terminal to indicate theterminal to switch to the narrow bandwidth specified in the switchingmessage for information reception, the narrow bandwidth being smallerthan a system bandwidth.

In a possible implementation mode, the switching method may furtherinclude the following operation.

DCI for the terminal may be sent in a PDCCH on the narrow bandwidth.

The DCI may be located in a User Equipment (UE)-specific search spacecorresponding to the terminal and adopt a CCE aggregation levelcorresponding to the terminal.

In a possible implementation mode, the switching method may furtherinclude the following operations.

A duration of narrow-band signal detection of the terminal in thenarrow-bandwidth receiving mode and an interval period of narrow-bandsignal detection may be pre-configured, and the duration of narrow-bandsignal detection and the interval period of narrow-band signal detectionmay be sent to the terminal.

Or, time information of stopping narrow-band signal detection andrestarting narrow-band signal detection may be sent to the terminal.

In a possible implementation mode, after the terminal may be switched tothe narrow bandwidth specified in the switching message for informationreception, the switching method may further include the followingoperation.

A frequency band index and a switching delay may be sent to the terminalto indicate the terminal to switch to another narrow bandwidth oranother system bandwidth.

Herein, the frequency band index may be configured to indicate thebandwidth that the terminal is to switch to at differentfrequency-domain positions, and the switching delay may be configured toindicate a time offset between a present moment and a moment when theterminal starts signal reception on the bandwidth indicated by thefrequency band index.

In a possible implementation mode, when the terminal is in thenarrow-bandwidth receiving mode, the switching method may furtherinclude the following operation.

A Physical Downlink Shared Channel (PDSCH) including downlink data maybe scheduled for the terminal in the PDCCH on the narrow bandwidth, thedownlink data being less than a preset capacity.

In a possible implementation mode, a frequency-domain resource of thePDSCH may be located within the narrow bandwidth, and the DCI sent inthe PDCCH on the narrow bandwidth may include a resource indexcorresponding to the frequency-domain resource allocated for the PDSCHand a Modulation and Coding Scheme (MCS) for the downlink data.

In a possible implementation mode, when the terminal is in thenarrow-bandwidth receiving mode, the switching method may furtherinclude the following operation.

A feedback acknowledgement signal and a Hybrid Auto Repeat Request(HARQ) process identifier for uplink transmission may be sent to theterminal in the PDCCH on the narrow bandwidth.

A second aspect of the embodiments of the disclosure provides aswitching method, which may include the following operations.

A terminal receives a switching message, configured by a base station,in a narrow-bandwidth receiving mode, the switching message includingtime when the terminal is indicated to enter the narrow-bandwidthreceiving mode and a position of a narrow bandwidth on a frequency bandwhen the narrow-bandwidth receiving mode is entered.

Switching to the narrow bandwidth specified in the switching message forinformation reception may be executed, the narrow bandwidth beingsmaller than a system bandwidth.

In a possible implementation mode, the switching method may furtherinclude the following operation.

DCI for the terminal in a PDCCH on the narrow bandwidth may be received.

The DCI may be located in a UE-specific search space corresponding tothe terminal and adopt a CCE aggregation level corresponding to theterminal.

In a possible implementation mode, the switching method may furtherinclude the following operations.

A duration of narrow-band signal detection of the terminal in thenarrow-bandwidth receiving mode and an interval period of narrow-bandsignal detection, which are pre-configured by the base station, may bereceived, and a receiver may be turned off in the interval period.

Or, time information of stopping narrow-band signal detection andrestarting narrow-band signal detection may be received from the basestation, the receiver may be turned off at a moment when narrow-bandsignal detection is stopped, and the receiver may be turned on at amoment when signal detection is restarted.

In a possible implementation mode, after the terminal is switched to thenarrow bandwidth specified in the switching message for informationreception, the switching method may further include the followingoperation.

A frequency band index and a switching delay may be received from thebase station, and switching to another narrow bandwidth or anothersystem bandwidth may be executed according to the frequency band indexand the switching delay.

Herein, the frequency band index may be configured to indicate thebandwidth that the terminal is to switch to at differentfrequency-domain positions, and the switching delay may be configured toindicate a time offset between a present moment and a moment when theterminal starts signal reception on the bandwidth indicated by thefrequency band index.

In a possible implementation mode, when the terminal is in thenarrow-bandwidth receiving mode, the switching method may furtherinclude the following operation.

A PDSCH scheduled for the terminal by the base station and includingdownlink data may be received in the PDCCH on the narrow bandwidth, thedownlink data being less than a preset capacity.

In a possible implementation mode, a frequency-domain resource of thePDSCH may be located within the narrow bandwidth, and the DCI receivedin the PDCCH on the narrow bandwidth may include a resource indexcorresponding to the frequency-domain resource allocated for the PDSCHand an MCS for the downlink data.

In a possible implementation mode, when the terminal is in thenarrow-bandwidth receiving mode, the switching method may furtherinclude the following operation.

A feedback acknowledgement signal and HARQ process identifier for uplinktransmission may be received from the base station in the PDCCH on thenarrow bandwidth.

A third aspect of the embodiments of the disclosure provides a basestation, which may include a configuration unit and a sending unit.

The configuration unit may be configured to configure a switchingmessage for a narrow-bandwidth receiving mode, the switching messageincluding time when a terminal is indicated to enter thenarrow-bandwidth receiving mode and a position of a narrow bandwidth ona frequency band when the narrow-bandwidth receiving mode is entered.

The sending unit may be configured to send the switching message to theterminal to indicate the terminal to switch to the narrow bandwidthspecified in the switching message for information reception, the narrowbandwidth being smaller than a system bandwidth.

In a possible implementation mode, the sending unit may further beconfigured to send DCI for the terminal in a PDCCH on the narrowbandwidth.

The DCI may be located in a UE-specific search space corresponding tothe terminal and use a CCE aggregation level corresponding to theterminal.

In a possible implementation mode, the configuration unit may further beconfigured to pre-configure a duration of narrow-band signal detectionof the terminal in the narrow-bandwidth receiving mode and an intervalperiod of narrow-band signal detection, and the sending unit may furtherbe configured to send the duration of narrow-band signal detection andthe interval period of narrow-band signal detection to the terminal.

Or, the sending unit may further be configured to send time informationof stopping narrow-band signal detection and restarting narrow-bandsignal detection to the terminal.

In a possible implementation mode, the sending unit may further beconfigured to, after the terminal is switched to the narrow bandwidthspecified in the switching message for information reception, send afrequency band index and a switching delay to the terminal to indicatethe terminal to switch to another narrow bandwidth or another systembandwidth.

Herein, the frequency band index may be configured to indicate thebandwidth that the terminal is to be switched to at differentfrequency-domain positions, and the switching delay may be configured toindicate a time offset between a present moment and a moment when theterminal starts signal reception on the bandwidth indicated by thefrequency band index.

In a possible implementation mode, the sending unit may further beconfigured to, when the terminal is in the narrow-bandwidth receivingmode, schedule a PDSCH including downlink data for the terminal in thePDCCH on the narrow bandwidth, the downlink data being less than apreset capacity.

In a possible implementation mode, a frequency-domain resource of thePDSCH may be located within the narrow bandwidth, and the DCI sent inthe PDCCH on the narrow bandwidth may include a resource indexcorresponding to the frequency-domain resource allocated for the PDSCHand an MCS for the downlink data.

In a possible implementation mode, the sending unit may further beconfigured to, when the terminal is in the narrow-bandwidth receivingmode, send A feedback acknowledgement signal and HARQ process identifierfor uplink transmission to the terminal in the PDCCH on the narrowbandwidth.

A fourth aspect of the embodiments of the disclosure provides a basestation, which may include:

a processor, a memory, a transceiver and a bus. The processor, thememory and the transceiver may be connected through the bus. Thetransceiver may be configured to send and receive signals andcommunicate with a terminal. The memory may be configured to store a setof program codes. The processor may be configured to call the programcodes stored in the memory to execute the following operations.

A switching message for a narrow-bandwidth receiving mode is configured,the switching message including time when a terminal is indicated toenter the narrow-bandwidth receiving mode and a position of a narrowbandwidth on a frequency band when the narrow-bandwidth receiving modeis entered.

The switching message is sent, through the transceiver, to the terminalto indicate the terminal to switch to the narrow bandwidth specified inthe switching message for information reception, the narrow bandwidthbeing smaller than a system bandwidth.

In a possible implementation mode, the processor may further beconfigured to send, through the transceiver, DCI for the terminal in aPDCCH on the narrow bandwidth.

The DCI may be located in a UE-specific search space corresponding tothe terminal and use a CCE aggregation level corresponding to theterminal.

In a possible implementation mode, the processor may further beconfigured to pre-configure a duration of narrow-band signal detectionof the terminal in the narrow-bandwidth receiving mode and an intervalperiod of narrow-band signal detection and send, through thetransceiver, the duration of narrow-band signal detection and theinterval period of narrow-band signal detection to the terminal,

or, send, through the transceiver, time information of stoppingnarrow-band signal detection and restarting narrow-band signal detectionto the terminal.

In a possible implementation mode, the processor may further beconfigured to, after the terminal is switched to the narrow bandwidthspecified in the switching message for information reception, send afrequency band index and a switching delay to the terminal to indicatethe terminal to switch to another narrow bandwidth or another systembandwidth.

Herein, the frequency band index may be configured to indicate thebandwidth that the terminal is to be switched to at differentfrequency-domain positions, and the switching delay may be configured toindicate a time offset between a present moment and a moment when theterminal starts signal reception on the bandwidth indicated by thefrequency band index.

In a possible implementation mode, the processor may further beconfigured to, when the terminal is in the narrow-bandwidth receivingmode, schedule a PDSCH including downlink data for the terminal in thePDCCH on the narrow bandwidth, the downlink data being less than apreset capacity.

In a possible implementation mode, a frequency-domain resource of thePDSCH may be located within the narrow bandwidth, and the DCI sent inthe PDCCH on the narrow bandwidth may include a resource indexcorresponding to the frequency-domain resource allocated for the PDSCHand an MCS for the downlink data.

In a possible implementation mode, the processor may further beconfigured to, when the terminal is in the narrow-bandwidth receivingmode, send, through the transceiver, A feedback acknowledgement signaland a HARQ process identifier for uplink transmission to the terminal inthe PDCCH on the narrow bandwidth.

A fifth aspect of the embodiments of the disclosure provides a terminal,which may include a receiving unit and a switching unit.

The receiving unit may be configured to receive a switching message,configured by a base station, in a narrow-bandwidth receiving mode, theswitching message including time when the terminal is indicated to enterthe narrow-bandwidth receiving mode and a position of a narrow bandwidthon a frequency band when the narrow-bandwidth receiving mode is entered.

The switching unit may execute switching to the narrow bandwidthspecified in the switching message for information reception, the narrowbandwidth being smaller than a system bandwidth.

In a possible implementation mode, the receiving unit may further beconfigured to receive DCI for the terminal in a PDCCH on the narrowbandwidth.

The DCI may be located in a UE-specific search space corresponding tothe terminal and use a CCE aggregation level corresponding to theterminal.

In a possible implementation mode, the receiving unit may further beconfigured to receive a duration of narrow-band signal detection of theterminal in the narrow-bandwidth receiving mode and an interval periodof narrow-band signal detection, which are pre-configured by the basestation, and turn off a receiver in the interval period;

or, receive time information of stopping narrow-band signal detectionand restarting narrow-band signal detection from the base station, turnoff the receiver at a moment when narrow-band signal detection isstopped and turn on the receiver at a moment when signal detection isrestarted.

In a possible implementation mode, the receiving unit may further beconfigured to, after the terminal is switched to the narrow bandwidthspecified in the switching message for information reception, receive afrequency band index and switching delay sent by the base station, andthe switching unit may further be configured to execute switching toanother narrow bandwidth or another system bandwidth according to thefrequency band index and the switching delay.

Herein, the frequency band index may be configured to indicate thebandwidth that the terminal is to be switched to at differentfrequency-domain positions, and the switching delay may be configured toindicate a time offset between a present moment and a moment when theterminal starts signal reception on the bandwidth indicated by thefrequency band index.

In a possible implementation mode, when the terminal is in thenarrow-bandwidth receiving mode, the receiving unit may further beconfigured to receive a PDSCH scheduled for the terminal by the basestation and including downlink data in the PDCCH on the narrowbandwidth, the downlink data being less than a preset capacity.

In a possible implementation mode, a frequency-domain resource of thePDSCH may be located within the narrow bandwidth, and the DCI receivedin the PDCCH on the narrow bandwidth may include a resource indexcorresponding to the frequency-domain resource allocated for the PDSCHand an MCS for the downlink data.

In a possible implementation mode, when the terminal is in thenarrow-bandwidth receiving mode, the receiving unit may further beconfigured to receive A feedback acknowledgement signal and a HARQprocess identifier for uplink transmission from the base station in thePDCCH on the narrow bandwidth.

A sixth aspect of the embodiments of the disclosure provides a terminal,which may include:

a processor, a memory, a transmitter, a receiver and a bus. Theprocessor, the memory, the transmitter and the receiver may be connectedthrough the bus. The transmitter may be configured to transmit a signal.The receiver may be configured to receive the signal. The transmitterand the receiver may be independently arranged respectively orintegrated. The memory may be configured to store a set of programcodes. The processor may be configured to call the program codes storedin the memory to execute the following operations.

A switching message, configured by a base station, in a narrow-bandwidthreceiving mode is received through the receiver, the switching messageincluding time when the terminal is indicated to enter thenarrow-bandwidth receiving mode and a position of a narrow bandwidth ona frequency band when the narrow-bandwidth receiving mode is entered.

Switching to the narrow bandwidth specified in the switching message forinformation reception is executed, the narrow bandwidth being smallerthan a system bandwidth.

In a possible implementation mode, the processor may further beconfigured to receive, through the receiver, DCI for the terminal in aPDCCH on the narrow bandwidth.

The DCI may be located in a UE-specific search space corresponding tothe terminal and adopt a CCE aggregation level corresponding to theterminal.

In a possible implementation mode, the processor may further beconfigured to receive, through the receiver, a duration of narrow-bandsignal detection of the terminal in the narrow-bandwidth receiving modeand an interval period of narrow-band signal detection, which arepre-configured by the base station, and turn off the receiver in theinterval period;

or, receive, through the receiver, time information of stoppingnarrow-band signal detection and restarting narrow-band signal detectionfrom the base station, turn off the receiver at a moment whennarrow-band signal detection is stopped and turn on the receiver at amoment when signal detection is restarted.

In a possible implementation mode, the processor may further beconfigured to, after the terminal is switched to the narrow bandwidthspecified in the switching message for information reception, receive,through the receiver, a frequency band index and switching delay sent bythe base station and execute switching to another narrow bandwidth oranother system bandwidth according to the frequency band index and theswitching delay.

Herein, the frequency band index may be configured to indicate thebandwidth that the terminal is to be switched to at differentfrequency-domain positions, and the switching delay may be configured toindicate a time offset between a present moment and a moment when theterminal starts signal reception on the bandwidth indicated by thefrequency band index.

In a possible implementation mode, the processor may further beconfigured to, when the terminal is in the narrow-bandwidth receivingmode, receive, through the receiver, a PDSCH scheduled for the terminalby the base station and including downlink data in the PDCCH on thenarrow bandwidth, the downlink data being less than a preset capacity.

In a possible implementation mode, a frequency-domain resource of thePDSCH may be located within the narrow bandwidth, and the DCI receivedin the PDCCH on the narrow bandwidth may include a resource indexcorresponding to the frequency-domain resource allocated for the PDSCHand an MCS for the downlink data.

In a possible implementation mode, the processor may further beconfigured to, when the terminal is in the narrow-bandwidth receivingmode, receive, through the receiver, A feedback acknowledgement signaland a HARQ process identifier for uplink transmission from the basestation in the PDCCH on the narrow bandwidth.

A seventh aspect of the embodiments of the disclosure provides acomputer storage medium, which includes a set of program codes toexecute the method in any implementation mode of the first aspect of theembodiments of the disclosure.

An eighth aspect of the embodiments of the disclosure provides acomputer storage medium, which includes a set of program codes toexecute the method in any implementation mode of the second aspect ofthe embodiments of the disclosure.

A ninth aspect of the embodiments of the disclosure provides a switchingmethod, which may include the following operations.

A base station configures a switching message for a narrow-bandwidthreceiving mode, the switching message including time when a terminal isindicated to enter the narrow-bandwidth receiving mode and a position ofa narrow bandwidth on a frequency band when the narrow-bandwidthreceiving mode is entered.

The switching message is sent to the terminal to indicate the terminalto switch to the narrow bandwidth specified in the switching message forinformation reception, the narrow bandwidth being smaller than a systembandwidth, the narrow bandwidth including a first narrow bandwidth or asecond narrow bandwidth, a PDCCH on the first narrow bandwidth includinga UE-specific search space and a PDCCH on the second narrow bandwidthincluding a common search space.

A tenth aspect of the embodiments of the disclosure provides a switchingmethod, which may include the following operations.

A terminal receives a switching message, configured by a base station,in a narrow-bandwidth receiving mode, the switching message includingtime when the terminal is indicated to enter the narrow-bandwidthreceiving mode and a position of a narrow bandwidth on a frequency bandwhen the narrow-bandwidth receiving mode is entered.

Switching to the narrow bandwidth specified in the switching message forinformation reception is executed, the narrow bandwidth being smallerthan a system bandwidth, the narrow bandwidth including a first narrowbandwidth or a second narrow bandwidth, a PDCCH on the first narrowbandwidth including a UE-specific search space and a PDCCH on the secondnarrow bandwidth including a common search space.

An eleventh aspect of the embodiments of the disclosure provides a basestation, which may include a configuration unit and a sending unit.

The configuration unit may be configured to configure a switchingmessage for a narrow-bandwidth receiving mode, the switching messageincluding time when a terminal is indicated to enter thenarrow-bandwidth receiving mode and a position of a narrow bandwidth ona frequency band when the narrow-bandwidth receiving mode is entered.

The sending unit may be configured to send the switching message to theterminal to indicate the terminal to switch to the narrow bandwidthspecified in the switching message for information reception, the narrowbandwidth being smaller than a system bandwidth, the narrow bandwidthincluding a first narrow bandwidth or a second narrow bandwidth, a PDCCHon the first narrow bandwidth including a UE-specific search space and aPDCCH on the second narrow bandwidth including a common search space.

A twelfth aspect of the embodiments of the disclosure provides a basestation, which may include:

a processor, a memory, a transceiver and a bus, the processor, thememory and the transceiver being connected through the bus, wherein thetransceiver is configured to send and receive signals and communicatewith a terminal, the memory is configured to store a set of programcodes, and the processor is configured to call the program codes storedin the memory to execute the steps in any implementation mode of theninth aspect of the disclosure.

A thirteenth aspect of the embodiments of the disclosure provides aterminal, which may include a receiving unit and a switching unit.

The receiving unit may be configured to receive a switching message,configured by a base station, in a narrow-bandwidth receiving mode, theswitching message including time when the terminal is indicated to enterthe narrow-bandwidth receiving mode and a position of a narrow bandwidthon a frequency band when the narrow-bandwidth receiving mode is entered.

The switching unit may be configured to execute switching to the narrowbandwidth specified in the switching message for information reception,the narrow bandwidth being smaller than a system bandwidth, the narrowbandwidth including a first narrow bandwidth or a second narrowbandwidth, a PDCCH on the first narrow bandwidth including a UE-specificsearch space, and a PDCCH on the second narrow bandwidth including acommon search space.

A fourteenth aspect of the embodiments of the disclosure provides aterminal, which may include:

a processor, a memory, a transmitter, a receiver and a bus, theprocessor, the memory, the transmitter and the receiver being connectedthrough the bus, wherein the transmitter is configured to transmit asignal, the receiver is configured to receive the signal, thetransmitter and the receiver are independently arranged respectively orintegrated, the memory is configured to store a set of program codes,and the processor is configured to call the program codes stored in thememory to execute the steps in any implementation mode of the tenthaspect of the disclosure.

A fifteenth aspect of the embodiments of the disclosure provides acomputer storage medium, which includes a set of program codes toexecute the method in any implementation mode of the ninth aspect of theembodiments of the disclosure.

A sixteenth aspect of the embodiments of the disclosure provides acomputer storage medium, which includes a set of program codes toexecute the method in any implementation mode of the tenth aspect of theembodiments of the disclosure.

Implementing the embodiments of the disclosure may achieve the followingbeneficial effects.

The base station configures a switching message to indicate anarrow-bandwidth receiving mode that the terminal is to be switched to,and in the narrow-bandwidth receiving mode, the terminal may receive asignal on the narrow bandwidth smaller than the system bandwidth, sothat the terminal is not required to detect the relatively large systembandwidth, power consumption of the terminal and a signal detectiondelay may be reduced. The PDCCH on the narrow bandwidth is configured toinclude the UE-specific search space and a fixed CCE aggregation levelonly, so that the amount of information detected by the terminal may bereduced, and the power consumption of the terminal may further bereduced. The base station may also indicate time when a narrow-bandsignal is detected and time during which the narrow-band signal is notdetected to the terminal in the narrow-bandwidth receiving mode andindicate the terminal to turn off the receiver when the narrow-bandsignal is not detected, so that energy consumption of the terminal mayfurther be reduced. The base station may further indicate the terminalto switch between the narrow bandwidth and the system bandwidth andbetween different narrow bandwidths, so that flexibility in use of thenarrow bandwidth is improved. Moreover, the base station may furtherschedule the downlink data less than the preset capacity orretransmission feedback information and HARQ process identifier foruplink transmission in the PDCCH on the narrow bandwidth, so thatfunctions of the narrow bandwidth are extended.

BRIEF DESCRIPTION OF DRAWINGS

In order to describe the technical solutions in the embodiments of thedisclosure or a conventional art more clearly, the drawings used indescriptions about the embodiments will be simply introduced below. Thedrawings described below are only some embodiments of the disclosure.Other drawings may further be obtained by those of ordinary skill in theart according to these drawings without creative work.

FIG. 1 is a schematic architecture diagram of a communication systemaccording to an embodiment of the disclosure.

FIG. 2 is a schematic flowchart of a first embodiment of a switchingmethod according to the disclosure.

FIG. 3 is a schematic flowchart of a second embodiment of a switchingmethod according to the disclosure.

FIG. 4 is a schematic flowchart of a third embodiment of a switchingmethod according to the disclosure.

FIG. 5 is a schematic diagram of signal reception on a narrow bandwidthby the switching method shown in FIG. 4.

FIG. 6 is a schematic flowchart of a fourth embodiment of a switchingmethod according to the disclosure.

FIG. 7 is a schematic diagram of frequency band indexes in the switchingmethod shown in FIG. 6.

FIG. 8 is a schematic diagram of scheduling of a narrow bandwidth in theswitching method shown in FIG. 6 according to the disclosure.

FIG. 9 is a schematic flowchart of a fifth embodiment of a switchingmethod according to the disclosure.

FIG. 10 is a schematic flowchart of a sixth embodiment of a switchingmethod according to the disclosure.

FIG. 11 is a schematic flowchart of a seventh embodiment of a switchingmethod according to the disclosure.

FIG. 12 is a schematic flowchart of an eighth embodiment of a switchingmethod according to the disclosure.

FIG. 13 is a composition diagram of a first embodiment of a base stationaccording to the disclosure.

FIG. 14 is a composition diagram of a second embodiment of a basestation according to the disclosure.

FIG. 15 is a composition diagram of a first embodiment of a terminalaccording to the disclosure.

FIG. 16 is a composition diagram of a second embodiment of a terminalaccording to the disclosure.

FIG. 17 is a schematic flowchart of a ninth embodiment of a switchingmethod according to the disclosure.

FIG. 18 is a schematic flowchart of a tenth embodiment of a switchingmethod according to the disclosure.

FIG. 19 is a schematic diagram of switching between different narrowbandwidths in the switching method shown in FIG. 18 according to thedisclosure.

FIG. 20 is a schematic flowchart of an eleventh embodiment of aswitching method according to the disclosure.

FIG. 21 is a schematic flowchart of a twelfth embodiment of a switchingmethod according to the disclosure.

FIG. 22 is a schematic flowchart of a thirteenth embodiment of aswitching method according to the disclosure.

FIG. 23 is a schematic flowchart of a fourteenth embodiment of aswitching method according to the disclosure.

FIG. 24 is a schematic flowchart of a fifteenth embodiment of aswitching method according to the disclosure.

FIG. 25 is a schematic flowchart of a sixteenth embodiment of aswitching method according to the disclosure.

FIG. 26 is a composition diagram of a third embodiment of a base stationaccording to the disclosure.

FIG. 27 is a composition diagram of a fourth embodiment of a basestation according to the disclosure.

FIG. 28 is a composition diagram of a third embodiment of a terminalaccording to the disclosure.

FIG. 29 is a composition diagram of a fourth embodiment of a terminalaccording to the disclosure.

DETAILED DESCRIPTION

Terms “include” and “have” in the specification, claims and drawings ofthe disclosure and any transformation thereof are intended to covernonexclusive inclusions. For example, a process, method, system, productor device including a series of steps or units is not limited to thesteps or units which have been listed but optionally further includessteps or units which are not listed or optionally further includes othersteps or units intrinsic to the process, the method, the product or thedevice.

Along with constant increase of communication requirements of people,communication technologies are developing fast, and larger bandwidths,higher uplink/downlink transmission speeds and the like may be providedfor users. For example, in a 5G system, a system bandwidth of 200 MHzmay be provided. However, along with extension of system bandwidths, ifa terminal receives a PDCCH on a large system bandwidth, powerconsumption of the terminal is high. Therefore, the embodiments of thedisclosure provide a switching method. Then, the terminal may beswitched to a narrow bandwidth smaller than the system bandwidth forwork, thereby reducing the power consumption of the terminal. Forconvenient description, descriptions will be made with a 5G system as anexample in the embodiments of the disclosure. Those skilled in the artshould know that the implementation modes in the embodiments of thedisclosure may also be applied to an existing communication system andfuture communication systems of higher levels such as 6-Generation (6G)and 7-Generation (7G). There are no limits made in the embodiments ofthe disclosure.

A switching method and device of the embodiments of the disclosure willbe described below in combination with the drawings in detail.

Referring to FIG. 1, an architecture diagram of a communication systemaccording to an embodiment of the disclosure is illustrated. Here, abase station and at least one terminal may be included in thecommunication system. The terminal may also be called UE.

Here, the base station may be an Evolved Node B (eNB), a Node B (NB), aBase Station Controller (BSC), a Base Transceiver Station (BTS), a homebase station (for example, a Home evolved NodeB or Home Node B (HNB)), aBaseBand Unit (BBU) and the like. It may also be called by those skilledin the art as a base station transceiver, a radio base station, a radiotransceiver, a transceiver function, a Base Station Subsystem (BSS) orsome other proper terms. The base station may bear scheduling DCI, in aPDCCH. The scheduling DCI may specifically include a transmissionformat, resource allocation, an uplink scheduling grant, power control,uplink retransmission information and the like. And the base station maytransmit downlink data of service to UE and receive a retransmissionfeedback and the like from the terminal.

Here, the terminal may include a cell phone, a smart phone, a SessionInitiation Protocol (SIP) phone, a laptop computer, a Personal DigitalAssistant (PDA), satellite ratio, a global positioning system, amultimedia device, a video device, a digital audio player (for example,a Moving Picture Experts Group Audio Layer-3 (MP3) player), a camera, agame console or any other device with a similar function. The terminalmay also be called by those skilled in the art as a mobile station, auser station, a mobile unit, a user unit, a radio unit, a remote unit, amobile device, a radio device, a radio communication device, a remotedevice, a mobile user station, an access terminal, a mobile terminal, aradio terminal, a remote terminal, a handheld device, a user agent, amobile client, a client or some other proper terms. The terminal mayreceive control information configured by the base station and atime/frequency-domain resource scheduled by the base station to transmituplink service data and retransmission feedback information.

For reducing power consumption of the terminal, the terminal may beconfigured to work on a narrow bandwidth smaller than the systembandwidth in the embodiments of the disclosure. The switching method ofthe disclosure will be described below in combination with FIG. 2-FIG. 8in detail.

Referring to FIG. 2, a schematic flowchart of a first embodiment of aswitching method according to the disclosure is illustrated. In theembodiment, the switching method includes the following steps.

In S201, a base station configures a switching message for anarrow-bandwidth receiving mode.

Here, the switching message includes time when the terminal is indicatedto enter the narrow-bandwidth receiving mode and a position of a narrowbandwidth on a frequency band when the narrow-bandwidth receiving modeis entered.

Optionally, the time when the narrow-bandwidth receiving mode is enteredmay include starting time for entering the narrow-bandwidth receivingmode. The terminal, after receiving the switching message, enters thenarrow-bandwidth receiving mode at the specified starting time and isswitched to a system bandwidth when receiving a message of stopping thenarrow-bandwidth receiving mode from the base station, or may also beswitched from the present narrow bandwidth to another narrow bandwidthor to the system bandwidth when receiving from the base station amessage of switching to the other narrow bandwidth or the systembandwidth.

The time when the narrow-bandwidth receiving mode is entered may furtherinclude termination time for entering the narrow-bandwidth receivingmode, besides the time when the narrow-bandwidth receiving mode isentered. The terminal may enter the narrow-bandwidth receiving mode atthe specified starting time and be switched back to the system bandwidthfor information reception at the specified termination time.

It is to be noted that a terminal supporting Machine Type Communications(MTC) may demodulate a downlink signal on a bandwidth of 1.4 MHz, i.e.,6 PRBs. For such a terminal, power consumption of the terminal may bereduced because of decrease of a downlink bandwidth. However, such aterminal may only work on a relatively narrow bandwidth, for example, 6PRBs, and thus functions of the terminal may be restricted more. Thenarrow bandwidth in the embodiment of the disclosure is smaller than thesystem bandwidth, that is, the narrow bandwidth in the embodiment of thedisclosure is a frequency-domain width smaller than the systembandwidth. This is a concept different from the 1.4 MHz bandwidth in anexisting 4G system. For example, 10 MHz and 20 MHz are typical systembandwidths in the existing 4G systems, and when the system bandwidth is10 MHz, the narrow bandwidth in the embodiment of the disclosure may bea bandwidth smaller than 10 MHz, for example, 2 MHz and 5 MHz; and whenthe system bandwidth is 20 MHz, the narrow bandwidth in the embodimentof the disclosure may be a bandwidth smaller than 20 MHz, for example, 5MHz, 10 MHz and 12 MHz. When the system bandwidth is 1.4 MHz, the narrowbandwidth in the embodiment of the disclosure may also be a bandwidthsmaller than 1.4 MHz, for example, 0.6 MHz. For a 5G system with alarger bandwidth, the narrow bandwidth may also be a bandwidth smallerthan the system bandwidth in the 5G system.

In S202, the switching message is sent to the terminal to indicate theterminal to switch to the narrow bandwidth specified in the switchingmessage for information reception.

Optionally, the base station may indicate the terminal, throughhigh-layer signaling such as Radio Resource Control (RRC) orphysical-layer signaling such as DCI, to switch to the mode of receivingthe narrow bandwidth only. The base station may indicate a specificmoment when the narrow-bandwidth receiving mode of the terminal isstarted and indicate a specific position of the narrow bandwidth on thefrequency band. Then, the terminal may be switched to a specified narrowbandwidth for information reception according to the switching message.In the narrow-bandwidth receiving mode, the terminal may retune its ownradio frequency bandwidth to a specified narrow bandwidth, i.e., afrequency-domain width indicated by a system for the terminal toreceive. For example, if the base station indicates that the narrowbandwidth of the terminal is 6 PRBs (which is 1.4 MHz, if taking a 15KHz subcarrier interval as an example), the terminal may retune its ownradio frequency unit to 6 PRBs at a frequency band position of thenarrow bandwidth indicated by the system. In such case, the terminal canreceive signals on the 6 PRBs only. Because of decrease of the receivingof radio frequency bandwidth, the terminal may achieve a power-savingeffect. The terminal may be not required to detect the signals on thelarge system bandwidth, but only required to receive and detect signalson the narrow bandwidth smaller than the system bandwidth, so that aworkload of the terminal is reduced, the power consumption of theterminal is reduced and signal receiving efficiency of the terminal isimproved.

It is to be noted that the power consumption of the terminal is mainlyreflected in two aspects. The first aspect is signal detection of theterminal on the whole system bandwidth and the second aspect is blinddetection over the terminal over a PDCCH. Blind detection over the PDCCHincludes detection of different CCE aggregation levels such as 2, 4 and8, different DCI lengths and the like. DCI detected by the terminal notonly includes DCI for a single terminal only, which is required to bedetected in a UE-specific search space, but also includes DCI formultiple terminals, which is required to be detected in a common searchspace. Since more contents are detected, the power consumption of theterminal is relatively high. In such case, switching may also beexecuted with reference to the switching method in FIG. 3.

Referring to FIG. 3, a schematic flowchart of a second embodiment of aswitching method according to the disclosure is illustrated. In theembodiment, S301-S302 are the same as S201-S202 in FIG. 2 and will notbe elaborated herein. In addition, the method further includes thefollowing step.

In S303, DCI for the terminal is sent in a PDCCH on the narrowbandwidth.

Here, the DCI is located in a UE-specific search space corresponding tothe terminal and uses a CCE aggregation level corresponding to theterminal.

In the narrow-bandwidth receiving mode, the PDCCH configured for thebase station to schedule the terminal is located on the narrow bandwidthindicated by the base station. For reducing complexity in receiving sucha PDCCH by the terminal, DCI for different single terminals rather thanDCI for all terminals on the narrow bandwidth may be contained in thePDCCH on the narrow bandwidth, or the PDCCH on the narrow bandwidthincludes the UE-specific search space only and does not include thecommon search space. Meanwhile, for the DCI for different singleterminals, the CCE aggregation level may be fixed. For example, the CCEaggregation level may be indicated to the terminal when the base stationconfigures the narrow-bandwidth receiving mode for the terminal.

In the embodiment of the disclosure, since the PDCCH includes theUE-specific search space and the fixed CCE aggregation level only, theamount of information required to be detected by the terminal whenreceiving the PDCCH on the narrow bandwidth can be reduced, and thepower consumption of the terminal may further be reduced.

Besides the bandwidth detected by the terminal and the amount of thedetected information are reduced, the terminal may also be configured toenter a dormant state or turn off a receiver at specified time in thenarrow-bandwidth receiving mode.

Specifically referring to FIG. 4, a schematic flowchart of a thirdembodiment of a switching method according to the disclosure isillustrated. In the embodiment, S401-S403 are the same as S301-S303 inFIG. 3 and will not be elaborated herein. The method further includesthe following step.

In S404, both a duration of narrow-band signal detection of the terminalin the narrow-bandwidth receiving mode and an interval period ofnarrow-band signal detection are pre-configured, the duration ofnarrow-band signal detection and the interval period of narrow-bandsignal detection are sent to the terminal, and the terminal is indicatedto turn off a receiver in the interval period.

Optionally, a narrow-band signal may include, but is not limited to: aPDCCH and/or a Physical Downlink Shared Channel (PDSCH). The basestation may pre-configure time during which the terminal is in thenarrow-bandwidth receiving mode. FIG. 5 is a schematic diagram of signalreception on a narrow bandwidth by the switching method shown in FIG. 4.In FIG. 5, the terminal is in the narrow-bandwidth receiving mode withintime T1˜T2, i.e., the duration of narrow-band signal detection. The basestation may also pre-configure time during which the terminal does notdetect the narrow-band PDCCH and/or the PDSCH that probably exists (insuch case, the terminal may turn off the receiver). Time T2˜T3 shown inFIG. 5 is the interval period of narrow-band signal detection. Theterminal, after entering the narrow-bandwidth receiving mode, regularly(periodically) detects the narrow-band signal (the narrow-band PDCCHand/or the PDSCH) according to a configuration of the base station, andmay turn off the receiver in other time to achieve a power-savingeffect.

Optionally, the base station may also send time information of stoppingnarrow-band signal detection and restarting narrow-band signal detectionto the terminal and indicate the terminal to turn off the receiver at amoment when narrow-band signal detection is stopped and turn on thereceiver at a moment when signal detection is restarted. A timer may beconfigured in the terminal for timing.

Moments T2˜T3 are shown in FIG. 5. After the moment T3, the terminalrestarts narrow-band signal detection. The base station indicates thespecific moments when detection is stopped and detection is restarted tothe terminal through the narrow-band PDCCH, for example, the DCI.

Or, the base station may also send the time information of stoppingnarrow-band signal detection to the terminal to indicate the terminal tocontrol the receiver to enter the dormant state at the moment whennarrow-band signal detection is stopped. In the dormant state, if thebase station sends a wakeup message to the terminal, the terminalmonitors the wakeup message sent by the base station and then turns onthe receiver.

When UE controls the receiver to enter the dormant state, there has beenno RRC connection or UE-specific resource. Therefore, in such case, theterminal may monitor a call channel and a broadcast channel, and whendetecting a wakeup message sent by the base station, the terminal mayturn on the receiver.

In the embodiment, the terminal in the narrow-bandwidth receiving modeis scheduled/pre-configured to detect the narrow-band signal in part oftime only, and the terminal may turn off the receiver in other time tofurther achieve the power-saving effect.

It is to be noted that the base station may send related timeinformation to the terminal and then the terminal determines whether thereceiver is required to be turned off within time during which thenarrow-band signal is not detected or not, or the base station may alsodirectly indicate the terminal to turn off the receiver within the timeduring which the narrow-band signal is not detected, when the basestation sends the related time information to the terminal. There are nolimits made in the embodiment of the disclosure.

Referring to FIG. 6, a schematic flowchart of a fourth embodiment of aswitching method according to the disclosure is illustrated. In theembodiment, S601-S602 are the same as S201-S202 in FIG. 2. The switchingmethod further includes the following step.

In S603, a frequency band index and a switching delay are sent to theterminal to indicate the terminal to switch to another narrow bandwidthor another system bandwidth.

Herein, the frequency band index is used to indicate the bandwidth thatthe terminal is to be switched to at different frequency-domainpositions, and the switching delay is used to indicate a time offsetbetween a present moment and a moment when the terminal starts signalreception on the bandwidth indicated by the frequency band index.

Optionally, the frequency band index may be configured and transmittedto the terminal by the base station, and may also be pre-stored in thebase station and the terminal, and when the base station sends thefrequency band index to the terminal, the terminal may look up a tableto determine the bandwidth that the terminal is to be switched to.

FIG. 7 is a schematic diagram of frequency band indexes in the fourthembodiment of the switching method of the disclosure. As shown in FIG.7, different frequency band indexes are directed to each possiblebandwidth at different frequency-domain positions. Frequency bandindexes of multiple narrow bandwidths at different frequency positionsmay be configured in a communication system. As shown in the figure,narrow bandwidths 1 and 2 correspond to frequency band indexes 2 and 4respectively. Frequency band indexes of multiple system bandwidths atdifferent frequency positions may also be configured. As shown in thefigure, system bandwidths 1 and 2 correspond to frequency band indexes 1and 3 respectively.

The terminal, after receiving the frequency band index and the switchingdelay from the base station, may be switched according to the frequencyband index and the switching delay. Here, switching may be switchingfrom a narrow bandwidth to the system bandwidth, and may also beswitching from a narrow bandwidth to another narrow bandwidth. FIG. 8 isa schematic diagram of scheduling of a narrow bandwidth in the switchingmethod shown in FIG. 6 according to the disclosure. The base station mayschedule the terminal from a narrow bandwidth 1 to a system bandwidth 1by use of a switching delay, and may also schedule the terminal from anarrow bandwidth 2 to a narrow bandwidth 3 by use of another differentswitching delay.

Of course, for switching from the system bandwidth to a narrow bandwidthin FIG. 2, the method of transmitting the frequency band index and theswitching delay in the fourth embodiment of the switching method of thedisclosure may also be adopted. There are no limits made in theembodiment of the disclosure.

Referring to FIG. 9, a schematic flowchart of a fifth embodiment of aswitching method according to the disclosure is illustrated. In theembodiment, S901-S904 are the same as S401-S404 in FIG. 4 and will notbe elaborated herein. When the terminal is in the narrow-bandwidthreceiving mode, the switching method further includes the followingsteps.

In S905, a PDSCH including downlink data is scheduled for the terminalin the PDCCH on the narrow bandwidth.

Herein, the downlink data is less than a preset capacity.

A frequency-domain resource of the PDSCH is located within the narrowbandwidth, and the DCI sent in the PDCCH on the narrow bandwidthincludes a resource index corresponding to the frequency-domain resourceallocated for the PDSCH and a Modulation and Coding Scheme (MCS) for thedownlink data.

When the terminal is in the narrow-bandwidth receiving mode, the basestation may also schedule the PDSCH including a small amount of data forthe terminal through the PDCCH on the narrow bandwidth on the basis of achannel capacity. The frequency-domain resource of the PDSCH scheduledon the narrow bandwidth is located within the narrow bandwidth, and theallocated resource and the MCS may be fixed or selected from a finiteset. For example, Table 1 is a schematic table of the MCS and resourceallocation of the narrow-band PDSCH.

MCSs Allocated resources Narrow bandwidth 1 MCS1, index: 1 Set1, index:1 MCS1, index: 1 Set2, index: 2 MCS1, index: 1 Set3, index: 3 Narrowbandwidth 2 MCS1, index: 1 Set4, index: 1 MCS1, index: 1 Set5, index: 2MCS2, index: 2 Set6, index: 3 MCS2, index: 2 Set7, index: 4

Herein, the MCSs and allocated resources on different narrow bandwidthsand a mapping relationship therebetween may be different. For example,for the narrow bandwidth 1, there is only one MCS and three possibleresource allocation sets; and for the narrow bandwidth 2, there are twoMCSs and four possible resource allocation sets. For different narrowbandwidths shown in Table 1, the relationship between the MCSs and theallocated resources may be pre-configured through high-layer signaling,for example, RRC signaling. The DCI sent in the narrow-band PDCCH mayinclude the MCS and the resource index corresponding to the resource.The resources corresponding to the narrow bandwidth 1 may be dividedinto more than two frequency bands, for example, set 1 and set 2,corresponding to resource index 1 and resource index 2 respectively andoccupying different frequency resources.

In 906, a feedback acknowledgement signal and HARQ process identifierfor uplink transmission are sent to the terminal in the PDCCH on thenarrow bandwidth.

Optionally, besides transmitting a small amount of downlink data, thefeedback acknowledgement signal (ACK/NACK) and HARQ process identifier(configured to distinguish different uplink transmission processes) foruplink transmission may also be transmitted in the narrow-bandwidthreceiving mode.

By transmitting the contents, functions of the narrow-bandwidthreceiving mode may be enriched, and functions of the narrow bandwidthmay be extended on the premise of ensuring low power consumption of theterminal.

It is to be noted that the embodiments of the switching method shown inFIG. 2-FIG. 9 may be independently implemented or may also be combinedfor implementation. There are no limits made in the embodiment of thedisclosure.

Referring to FIG. 10, a schematic flowchart of a sixth embodiment of aswitching method according to the disclosure is illustrated. In theembodiment, the switching method includes the following steps.

In S1001, a terminal receives a switching message, configured by a basestation, in a narrow-bandwidth receiving mode.

The switching message includes time when the terminal is indicated toenter the narrow-bandwidth receiving mode and a position of the narrowbandwidth on a frequency band when the narrow-bandwidth receiving modeis entered.

In S1002, switching to the narrow bandwidth specified in the switchingmessage for information reception is executed.

Herein, the narrow bandwidth is smaller than a system bandwidth.

FIG. 10 shows embodiment descriptions made from a terminal side, and aspecific process may refer to embodiment descriptions, shown in FIG. 2,made from a base station side and will not be elaborated herein.

Referring to FIG. 11, a schematic flowchart of a seventh embodiment of aswitching method according to the disclosure is illustrated. Comparedwith the embodiment shown in FIG. 10, the switching method in theembodiment further includes the following step.

In S1103, DCI for the terminal in a PDCCH on the narrow bandwidth isreceived.

Herein, the DCI is located in a UE-specific search space correspondingto the terminal and uses a CCE aggregation level corresponding to theterminal.

FIG. 11 shows embodiment descriptions made from the terminal side, and aspecific process may refer to embodiment descriptions, shown in FIG. 3,made from the base station side and will not be elaborated herein.

Referring to FIG. 12, a schematic flowchart of an eighth embodiment of aswitching method according to the disclosure is illustrated. Comparedwith the embodiment shown in FIG. 11, the switching method in theembodiment further includes the following step.

In S1204, a duration of narrow-band signal detection of the terminal inthe narrow-bandwidth receiving mode and an interval period ofnarrow-band signal detection, which are pre-configured by the basestation, are received, and a receiver is turned off in the intervalperiod.

Optionally, in the embodiment, the method may further include thefollowing operations:

the duration of narrow-band signal detection of the terminal in thenarrow-bandwidth receiving mode and the interval period of narrow-bandsignal detection, which are pre-configured by the base station, arereceived, and the receiver is turned off in the interval period;

or, time information of stopping narrow-band signal detection andrestarting narrow-band signal detection is received from the basestation, the receiver is turned off at a moment when narrow-band signaldetection is stopped, and the receiver is turned on at a moment whensignal detection is restarted.

After the terminal is switched to the narrow bandwidth specified in theswitching message for information reception, the switching methodfurther includes the following operation:

a frequency band index and switching delay are received from the basestation, and switching to another narrow bandwidth or another systembandwidth is executed according to the frequency band index and theswitching delay.

Herein, the frequency band index is used to indicate the bandwidth thatthe terminal is to be switched to at different frequency-domainpositions, and the switching delay is used to indicate a time offsetbetween a present moment and a moment when the terminal starts signalreception on the bandwidth indicated by the frequency band index.

When the terminal is in the narrow-bandwidth receiving mode, theswitching method further includes the following operation:

a PDSCH scheduled for the terminal by the base station and includingdownlink data is received in the PDCCH on the narrow bandwidth, thedownlink data being less than a preset capacity.

A frequency-domain resource of the PDSCH is located within the narrowbandwidth, and the DCI received in the PDCCH on the narrow bandwidthincludes a resource index corresponding to the frequency-domain resourceallocated for the PDSCH and an MCS for the downlink data.

Optionally, when the terminal is in the narrow-bandwidth receiving mode,the switching method further includes the following operation:

A feedback acknowledgement signal and HARQ process identifier for uplinktransmission are received from the base station in the PDCCH on thenarrow bandwidth.

FIG. 12 shows embodiment descriptions made from the terminal side, and aspecific process may refer to embodiment descriptions, shown in FIG.4-FIG. 9, made from the base station side and will not be elaboratedherein.

Referring to FIG. 13, a composition diagram of a first embodiment of abase station according to the disclosure is illustrated. In theembodiment, the base station includes a configuration unit 100 and asending unit 200.

The configuration unit 100 is configured to configure a switchingmessage for a narrow-bandwidth receiving mode, the switching messageincluding time when a terminal is indicated to enter thenarrow-bandwidth receiving mode and a position of a narrow bandwidth ona frequency band when the narrow-bandwidth receiving mode is entered.

The sending unit 200 is configured to send the switching message to theterminal to indicate the terminal to switch to the narrow bandwidthspecified in the switching message for information reception, the narrowbandwidth being smaller than a system bandwidth.

Optionally, the sending unit 200 is further configured to send DCI forthe terminal in a PDCCH on the narrow bandwidth.

The DCI is located in a UE-specific search space corresponding to theterminal and uses a CCE aggregation level corresponding to the terminal.

Optionally, the configuration unit 100 is further configured topre-configure a duration of narrow-band signal detection of the terminalin the narrow-bandwidth receiving mode and an interval period ofnarrow-band signal detection, and the sending unit 200 is furtherconfigured to send information about the duration of narrow-band signaldetection and the interval period of narrow-band signal detection to theterminal.

Or, the sending unit 200 is further configured to send time informationof stopping narrow-band signal detection and restarting narrow-bandsignal detection to the terminal.

Optionally, the sending unit 200 is further configured to, after theterminal is switched to the narrow bandwidth specified in the switchingmessage for information reception, send a frequency band index and aswitching delay to the terminal to indicate the terminal to switch toanother narrow bandwidth or another system bandwidth.

Herein, the frequency band index is used to indicate the bandwidth thatthe terminal is to be switched to at different frequency-domainpositions, and the switching delay is used to indicate a time offsetbetween a present moment and a moment when the terminal starts signalreception on the bandwidth indicated by the frequency band index.

Optionally, the sending unit 200 is further configured to, when theterminal is in the narrow-bandwidth receiving mode, schedule a PDSCHincluding downlink data for the terminal in the PDCCH on the narrowbandwidth, the downlink data being less than a preset capacity.

Optionally, a frequency-domain resource of the PDSCH is located withinthe narrow bandwidth, and the DCI sent in the PDCCH on the narrowbandwidth includes a resource index corresponding to thefrequency-domain resource allocated for the PDSCH and an MCS for thedownlink data.

Optionally, the sending unit 200 is further configured to, when theterminal is in the narrow-bandwidth receiving mode, send a feedbackacknowledgement signal and HARQ process identifier for uplinktransmission to the terminal in the PDCCH on the narrow bandwidth.

Referring to FIG. 14, a composition diagram of a second embodiment of abase station according to the disclosure is illustrated. In theembodiment, the base station includes:

a processor 110, a memory 120, a transceiver 130 and a bus 140. Theprocessor 110, the memory 120 and the transceiver 130 are connectedthrough the bus 140. The transceiver 130 is configured to send andreceive signals and communicate with a terminal. The memory 120 isconfigured to store a set of program codes. The processor 110 isconfigured to call the program codes stored in the memory 120 to executethe following operations:

a switching message for a narrow-bandwidth receiving mode is configured,the switching message including time when a terminal is indicated toenter the narrow-bandwidth receiving mode and a position of a narrowbandwidth on a frequency band when the narrow-bandwidth receiving modeis entered; and

the switching message is sent, through the transceiver 130, to theterminal to indicate the terminal to switch to the narrow bandwidthspecified in the switching message for information reception, the narrowbandwidth being smaller than a system bandwidth.

Optionally, the processor 110 is further configured to send, through thetransceiver 130, DCI for the terminal in a PDCCH on the narrowbandwidth.

The DCI is located in a UE-specific search space corresponding to theterminal and uses a CCE aggregation level corresponding to the terminal.

Optionally, the processor 110 is further configured to: pre-configure aduration of narrow-band signal detection of the terminal in thenarrow-bandwidth receiving mode and an interval period of narrow-bandsignal detection and send, through the transceiver 130, the duration ofnarrow-band signal detection and the interval period of narrow-bandsignal detection to the terminal,

or, send, through the transceiver 130, time information of stoppingnarrow-band signal detection and restarting narrow-band signal detectionto the terminal.

Optionally, the processor 110 is further configured to, after theterminal is switched to the narrow bandwidth specified in the switchingmessage for information reception, send a frequency band index and aswitching delay to the terminal to indicate the terminal to switch toanother narrow bandwidth or another system bandwidth.

Herein, the frequency band index is used to indicate the bandwidth thatthe terminal is to be switched to at different frequency-domainpositions, and the switching delay is used to indicate a time offsetbetween a present moment and a moment when the terminal starts signalreception on the bandwidth indicated by the frequency band index.

Optionally, the processor 110 is further configured to, when theterminal is in the narrow-bandwidth receiving mode, schedule a PDSCHincluding downlink data for the terminal in the PDCCH on the narrowbandwidth, the downlink data being less than a preset capacity.

Optionally, a frequency-domain resource of the PDSCH is located withinthe narrow bandwidth, and the DCI sent in the PDCCH on the narrowbandwidth includes a resource index corresponding to thefrequency-domain resource allocated for the PDSCH and an MCS for thedownlink data.

Optionally, the processor 110 is further configured to, when theterminal is in the narrow-bandwidth receiving mode, send, through thetransceiver 130, a feedback acknowledgement signal and HARQ processidentifier for uplink transmission to the terminal in the PDCCH on thenarrow bandwidth.

Referring to FIG. 15, a composition diagram of a first embodiment of aterminal according to the disclosure is illustrated. In the embodiment,the terminal includes a receiving unit 300 and a switching unit 400.

The receiving unit 300 is configured to receive a switching message,configured by a base station, in a narrow-bandwidth receiving mode, theswitching message including time when the terminal is indicated to enterthe narrow-bandwidth receiving mode and a position of a narrow bandwidthon a frequency band when the narrow-bandwidth receiving mode is entered.

The switching unit 400 executes switching to the narrow bandwidthspecified in the switching message for information reception, the narrowbandwidth being smaller than a system bandwidth.

Optionally, the receiving unit 300 is further configured to receive DCIfor the terminal in a PDCCH on the narrow bandwidth.

The DCI is located in a UE-specific search space corresponding to theterminal and uses a CCE aggregation level corresponding to the terminal.

Optionally, the receiving unit 300 is further configured to receive aduration of narrow-band signal detection of the terminal in thenarrow-bandwidth receiving mode and an interval period of narrow-bandsignal detection, which are pre-configured by the base station, and turnoff a receiver in the interval period;

or, receive time information of stopping narrow-band signal detectionand restarting narrow-band signal detection from the base station, turnoff the receiver at a moment when narrow-band signal detection isstopped and turn on the receiver at a moment when signal detection isrestarted.

Optionally, the receiving unit 300 is further configured to, after theterminal is switched to the narrow bandwidth specified in the switchingmessage for information reception, receive a frequency band index and aswitching delay from the base station, and the switching unit 400 isfurther configured to execute switching to another narrow bandwidth oranother system bandwidth according to the frequency band index and theswitching delay.

Herein, the frequency band index is used to indicate the bandwidth thatthe terminal is to be switched to at different frequency-domainpositions, and the switching delay is used to indicate a time offsetbetween a present moment and a moment when the terminal starts signalreception on the bandwidth indicated by the frequency band index.

Optionally, when the terminal is in the narrow-bandwidth receiving mode,the receiving unit 300 is further configured to receive a PDSCHscheduled for the terminal by the base station and including downlinkdata in the PDCCH on the narrow bandwidth, the downlink data being lessthan a preset capacity.

Optionally, a frequency-domain resource of the PDSCH is located withinthe narrow bandwidth, and the DCI received in the PDCCH on the narrowbandwidth includes a resource index corresponding to thefrequency-domain resource allocated for the PDSCH and an MCS for thedownlink data.

Optionally, when the terminal is in the narrow-bandwidth receiving mode,the receiving unit 300 is further configured to receive a feedbackacknowledgement signal and HARQ process identifier for uplinktransmission from the base station in the PDCCH on the narrow bandwidth.

Referring to FIG. 16, a composition diagram of a second embodiment of aterminal according to the disclosure is illustrated. In the embodiment,the terminal includes:

a processor 210, a memory 220, a transmitter 230, a receiver 240 and abus 250. The processor 210, the memory 220, the transmitter 230 and thereceiver 240 are connected through the bus 250. The transmitter 230 isconfigured to transmit a signal. The receiver 240 is configured toreceive the signal. The transmitter 230 and the receiver 240 areindependently arranged respectively or integrated. The memory 220 isconfigured to store a set of program codes. The processor 210 isconfigured to call the program codes stored in the memory 220 to executethe following operations.

A switching message, configured by a base station, in a narrow-bandwidthreceiving mode is received through the receiver 240, the switchingmessage including time when the terminal is indicated to enter thenarrow-bandwidth receiving mode and a position of a narrow bandwidth ona frequency band when the narrow-bandwidth receiving mode is entered.

Switching to the narrow bandwidth specified in the switching message forinformation reception is executed, the narrow bandwidth being smallerthan a system bandwidth.

Optionally, the processor 210 is further configured to receive, throughthe receiver 240, DCI for the terminal in a PDCCH on the narrowbandwidth.

The DCI is located in a UE-specific search space corresponding to theterminal and uses a CCE aggregation level corresponding to the terminal.

Optionally, the processor 210 is further configured to receive, throughthe receiver 240, a duration of narrow-band signal detection of theterminal in the narrow-bandwidth receiving mode and an interval periodof narrow-band signal detection, which are pre-configured by the basestation, and turn off the receiver 240 in the interval period;

or, receive, through the receiver 240, time information of stoppingnarrow-band signal detection and restarting narrow-band signal detectionfrom the base station, turn off the receiver 240 at a moment whennarrow-band signal detection is stopped and turn on the receiver 240 ata moment when signal detection is restarted.

Optionally, the processor 210 is further configured to, after theterminal is switched to the narrow bandwidth specified in the switchingmessage for information reception, receive, through the receiver 240, afrequency band index and a switching delay from the base station andexecute switching to another narrow bandwidth or another systembandwidth according to the frequency band index and the switching delay.

Herein, the frequency band index is used to indicate the bandwidth thatthe terminal is to be switched to at different frequency-domainpositions, and the switching delay is used to indicate a time offsetbetween a present moment and a moment when the terminal starts signalreception on the bandwidth indicated by the frequency band index.

Optionally, the processor 210 is further configured to, when theterminal is in the narrow-bandwidth receiving mode, receive, through thereceiver 240, a PDSCH scheduled for the terminal by the base station andincluding downlink data in the PDCCH on the narrow bandwidth, thedownlink data being less than a preset capacity.

Optionally, a frequency-domain resource of the PDSCH is located withinthe narrow bandwidth, and the DCI received in the PDCCH on the narrowbandwidth includes a resource index corresponding to thefrequency-domain resource allocated for the PDSCH and an MCS for thedownlink data.

Optionally, the processor 210 is further configured to, when theterminal is in the narrow-bandwidth receiving mode, receive, through thereceiver 240, a feedback acknowledgement signal and HARQ processidentifier for uplink transmission from the base station in the PDCCH onthe narrow bandwidth.

When the terminal in the narrow-bandwidth receiving mode and if thePDCCH of a system includes the UE-specific search space only and doesnot include a common search space, a power-saving effect may beachieved, but the base station is also required to broadcast somecontrol signaling to UE through the common search space under somecircumstances. In such case, methods of FIG. 17-FIG. 25 may be adoptedfor narrow-band switching and detection.

Referring to FIG. 17, a schematic flowchart of a ninth embodiment of aswitching method according to the disclosure is illustrated. In theembodiment, the switching method includes the following steps.

In S1701, a base station configures a switching message for anarrow-bandwidth receiving mode.

Herein, the switching message includes time when a terminal is indicatedto enter the narrow-bandwidth receiving mode and a position of a narrowbandwidth on a frequency band when the narrow-bandwidth receiving modeis entered.

Optionally, the time when the narrow-bandwidth receiving mode is enteredmay include starting time for entering the narrow-bandwidth receivingmode. The terminal, after receiving the switching message, enters thenarrow-bandwidth receiving mode at the specified starting time and isswitched to the system bandwidth when receiving a message of stoppingthe narrow-bandwidth receiving mode from the base station, or may alsobe switched from the present narrow bandwidth to another narrowbandwidth or the system bandwidth when receiving a message of switchingto another narrow bandwidth or the system bandwidth from the basestation.

The time when the narrow-bandwidth receiving mode is entered may furtherinclude termination time for entering the narrow-bandwidth receivingmode, besides the time when the narrow-bandwidth receiving mode isentered. The terminal may enter the narrow-bandwidth receiving mode atthe specified starting time and be switched back to the system bandwidthfor information reception at the specified termination time.

It is to be noted that a terminal supporting MTC may demodulate adownlink signal on a bandwidth of 1.4 MHz, i.e., 6 PRBs. For such aterminal, power consumption of the terminal may be reduced because ofdecrease of a downlink bandwidth. However, such a terminal can work on arelatively narrow bandwidth only, for example, 6 PRBs, and thusfunctions of the terminal may be restricted more. The narrow bandwidthin the embodiment of the disclosure is smaller than the systembandwidth, that is, the narrow bandwidth in the embodiment of thedisclosure is a frequency-domain width smaller than the systembandwidth. This is different from the 1.4 MHz bandwidth in an existing4G system. For example, 10 MHz and 20 MHz are typical system bandwidthsin an existing 4G system, and when the system bandwidth is 10 MHz, thenarrow bandwidth in the embodiment of the disclosure may be a bandwidthsmaller than 10 MHz, for example, 2 MHz or 5 MHz; and when the systembandwidth is 20 MHz, the narrow bandwidth in the embodiment of thedisclosure may be a bandwidth smaller than 20 MHz, for example, 5 MHz,10 MHz or 12 MHz. When the system bandwidth is 1.4 MHz, the narrowbandwidth in the embodiment of the disclosure may also be a bandwidthsmaller than 1.4 MHz, for example, 0.6 MHz. For a 5G system with alarger bandwidth, the narrow bandwidth may also be a bandwidth smallerthan the system bandwidth in the 5G system.

In S1702, the switching message is sent to the terminal to indicate theterminal to switch to the narrow bandwidth specified in the switchingmessage for information reception.

Optionally, the base station may indicate the terminal throughhigh-layer signaling such as RRC or physical-layer signaling such as DCIto switch to the mode of receiving the narrow bandwidth only. The basestation may indicate a specific moment when the narrow-bandwidthreceiving mode of the terminal is started and a specific position of thenarrow bandwidth on the frequency band. Then, the terminal may beswitched to a specified narrow bandwidth for information receptionaccording to the switching message. In the narrow-bandwidth receivingmode, the terminal may retune its own radio frequency bandwidth to aspecified narrow bandwidth, i.e., a receiving frequency-domain widthindicated by a system for the terminal. For example, if the base stationindicates that the narrow bandwidth of the terminal is 6 PRBs (which is1.4 MHz if taking a 15 KHz subcarrier interval as an example), theterminal may retune its own radio frequency unit to 6 PRBs at afrequency band position of the narrow bandwidth indicated by the system.In such case, the terminal may receive signals on the 6 PRBs. Because ofdecrease of the receiving of radio frequency bandwidth, the terminal mayachieve a power-saving effect. The terminal may be not required todetect the signals on the large system bandwidth, and is only requiredto receive and detect signals on the narrow bandwidth smaller than thesystem bandwidth, so that a workload of the terminal is reduced, thepower consumption of the terminal is reduced and the efficiency ofsignal reception of the terminal is improved.

It is to be noted that the narrow bandwidth may include a first narrowbandwidth or a second narrow bandwidth; a PDCCH on the first narrowbandwidth includes a UE-specific search space and a PDCCH on the secondnarrow bandwidth includes a common search space. Then, for achieving apurpose of broadcasting some control signaling to UE in the commonsearch space, the terminal may be indicated to switch from the firstnarrow bandwidth to the second narrow bandwidth. Here, for convenientdescription, only the first narrow bandwidth and the second narrowbandwidth are used, and of course, a third narrow bandwidth, a fourthnarrow bandwidth or the like, including a narrow bandwidth including theUE-specific search space and a narrow bandwidth including the commonsearch space, may also exist. Besides the narrow bandwidth including thecommon search space, the base station may also indicate the terminal toswitch to a system bandwidth including the common search space fordetection.

Three switching manners will be introduced below in detail.

Referring to FIG. 18, a schematic flowchart of a tenth embodiment of aswitching method according to the disclosure is illustrated. In theembodiment, S1801-S1802 are the same as S1701-S1702. When switchingbetween the first narrow bandwidth and the second narrow bandwidth isrequired, the switching method further includes the following steps.

In S1803, the base station configures detection parameters for theterminal for detection on the first narrow bandwidth and the secondnarrow bandwidth respectively.

The detection parameter includes a detection time bucket, or includes adetection period, a starting moment and a single detection duration.

For example, the base station may configure different narrow bandwidthsfor the terminal, some narrow bandwidths including the UE-specificsearch space and some narrow bandwidths including the common searchspace. The base station may directly indicate to the terminal a timebucket during which detection on the narrow bandwidths including theUE-specific search space is performed and a time bucket during whichdetection on the narrow bandwidths including the common search space isperformed. Besides indicating the specific time buckets, differentdetection periods, starting moments and single detection durations mayalso be configured for different narrow bandwidths. For example, for thefirst narrow bandwidth, the detection period is L1, the starting momentis T1 and the single detection duration is (T2-T1), and then theterminal may be switched to the first narrow bandwidth for detection ina fixed time bucket in each period.

In S1804, the detection parameters are sent to the terminal to indicatethe terminal to execute switching and detection according to thedetection parameters.

The detection parameters may be specifically configured to indicate theterminal to execute switching and detection on different narrowbandwidths.

FIG. 19 is a schematic diagram of switching between different narrowbandwidths in the switching method shown in FIG. 18 according to thedisclosure.

As shown in FIG. 19, the first narrow bandwidth (narrow bandwidth 1,corresponding to a narrow-band PDCCH 1) and the second narrow bandwidth(narrow bandwidth 2, corresponding to a narrow-band PDCCH 2) areincluded, and frequency-domain positions of the two narrow bandwidthsmay be partially overlapped or completely not overlapped (as shown inFIG. 19, they are completely not overlapped). The base station mayconfigure the terminal to perform detection on different narrowbandwidths in different time buckets. As shown in FIG. 19, the terminalperforms detection on the narrow bandwidth 1 in time T1˜T2 and T5˜T6,and the terminal performs detection on the narrow bandwidth 2 in timeT3˜T4 and T7˜T8. The time T2˜T3, T4˜T5 and T6˜T7 is time when theterminal is retuned between different narrow bandwidths. The system mayindicate the time when to detect a specific narrow bandwidth to theterminal in a manner of time pattern, and may also specifically indicatesymbols where detection on the specific narrow bandwidth is performedand symbols configured for retuning.

Or, the detection period, the starting moment and the single detectionduration may also be indicated to implement periodic detection. Forexample, the base station may configure different detection periods,starting moments and single detection durations for different narrowbandwidths. For example, as shown in FIG. 19, for the narrow bandwidth,the period is L1, the starting moment is T1 (in a possibleimplementation mode, a termination moment for detection, for example,T2, may also be configured) and the single detection duration is(T2−T1); and for the bandwidth 2, the period is L2, the starting momentT3 and the single detection duration is (T4−T3). Then, when entering thenext period, the terminal may be switched to the narrow bandwidth 1again for detection in T5˜T6 and switched to the narrow bandwidth 2again for detection in T7˜T8 according to these detection parameters.

For the terminal having entered a connected state, the base stationusually may not send control signaling frequently to the terminalthrough the common search space. Therefore, besides the switching methodof FIG. 18-FIG. 19, the method of FIG. 20 may also be adopted forswitching.

Referring to FIG. 20, a schematic flowchart of an eleventh embodiment ofa switching method according to the disclosure is illustrated. In theembodiment, S2001-S2002 are the same as S1701-S1702. When switchingbetween the first narrow bandwidth and the second narrow bandwidth isrequired, the switching method further includes the following steps.

In S2003, DCI for the terminal is sent in a PDCCH on the first narrowbandwidth to trigger the terminal to detect a common search space in aPDCCH on the second narrow bandwidth.

Optionally, the DCI includes a time-frequency position of the secondnarrow bandwidth, a detection duration of the terminal and a narrowbandwidth required to be monitored by the terminal after detection.

Then, the base station may trigger the terminal to detect the commonsearch space on another narrow bandwidth, for example, the second narrowbandwidth (or the system bandwidth), through the DCI in the UE-specificsearch space in the PDCCH sent on the first narrow bandwidth. The DCImay indicate to the terminal the time-frequency position of the secondnarrow bandwidth (or the PDCCH), the detection duration of the terminaland the narrow bandwidth required to be monitored by the terminal afterdetection. Here, the base station may indicate the terminal to return tothe original first narrow bandwidth or allocate a narrow bandwidth forthe terminal to monitor, and if the new narrow bandwidth is allocatedfor monitoring, information about the new narrow bandwidth, such as aposition of the narrow bandwidth and retuning time for the terminal, isrequired to be provided for the terminal.

According to the method of triggering the terminal to monitor the commonsearch space through the DCI in the UE-specific search space, theterminal is triggered according to a requirement, so that a good powerconsumption reduction effect is achieved.

When the method of triggering through the DCI is adopted to implementnarrow bandwidth switching and if channel quality of the UE-specificsearch space is reduced, there may exist DCI triggering signaling loss.Therefore, the switching method of FIG. 21 may also be adopted forswitching.

Referring to FIG. 21, a schematic flowchart of a twelfth embodiment of aswitching method according to the disclosure is illustrated. In theembodiment, S2101-S2102 are the same as S1701-S1702. When switchingbetween the first narrow bandwidth and the second narrow bandwidth isrequired, the switching method further includes the following steps.

In S2103, the base station configures a period for detection on thesecond narrow bandwidth.

In S2104, information about the period is sent to the terminal toindicate the terminal to detect the common search space in the PDCCH onthe second narrow bandwidth according to the period.

In S2105, if switching between the first narrow bandwidth and the secondnarrow bandwidth is required in the period, the DCI for the terminal issent in the PDCCH on the first narrow bandwidth to trigger the terminalto detect the common search space in the PDCCH on the second narrowbandwidth.

Optionally, the DCI includes the time-frequency position of the secondnarrow bandwidth, the detection duration of the terminal and the narrowbandwidth required to be monitored by the terminal after detection.

The base station may configure the second narrow bandwidth including thecommon search space for the terminal. Here, the second narrow bandwidthmay also be replaced with the system bandwidth. The base station mayconfigure a relatively long detection period for the second narrowbandwidth, and then the terminal may perform detection on the secondnarrow bandwidth including the common search space at a relatively longtime interval. Meanwhile, when switching is required in the detectionperiod, the base station may also trigger the terminal to performdetection on the second narrow bandwidth including the common searchspace through the DCI in the UE-specific search space on the firstnarrow bandwidth.

Herein, a triggering frequency is not limited in the disclosure. Whenthe detection period is reached, the terminal may perform detection onthe common search space on the second narrow bandwidth again accordingto the period. Or, the base station may also configure a preset durationconfigured to indicate the terminal to temporarily stop performingdetection on the second narrow bandwidth according to the period, sendthe preset duration to the terminal to indicate the terminal totemporarily stop performing detection on the second narrow bandwidthaccording to the period within the preset duration, and if switchingbetween the first narrow bandwidth and the second narrow bandwidth isrequired in the preset duration, sends the DCI for the terminal again inthe PDCCH on the first narrow bandwidth to trigger the terminal todetect the common search space in the PDCCH on the second narrowbandwidth. Therefore, excessive detection may be reduced, and the powerconsumption may be reduced.

Referring to FIG. 22, a schematic flowchart of a thirteenth embodimentof a switching method according to the disclosure is illustrated. In theembodiment, the switching method includes the following steps.

In S2201, a terminal receives a switching message, configured by a basestation, in a narrow-bandwidth receiving mode.

The switching message includes time when the terminal is indicated toenter the narrow-bandwidth receiving mode and a position of the narrowbandwidth on a frequency band when the narrow-bandwidth receiving modeis entered.

In S2202, switching to the narrow bandwidth specified in the switchingmessage for information reception is executed.

Herein, the narrow bandwidth is smaller than a system bandwidth. Thenarrow bandwidth may include a first narrow bandwidth or a second narrowbandwidth, a PDCCH on the first narrow bandwidth includes a UE-specificsearch space and a PDCCH on the second narrow bandwidth includes acommon search space.

FIG. 22 shows embodiment descriptions made from a terminal side, and aspecific process may refer to embodiment descriptions, shown in FIG. 17,made from a base station side and will not be elaborated herein.

Referring to FIG. 23, a schematic flowchart of a fourteenth embodimentof a switching method according to the disclosure is illustrated.Compared with the embodiment shown in FIG. 22, when switching betweenthe first narrow bandwidth and the second narrow bandwidth is required,the switching method in the embodiment further includes the followingsteps.

In S2303, the terminal receives detection parameters sent by the basestation.

The detection parameters are detection parameters configured by the basestation for the terminal for detection on the first narrow bandwidth andthe second narrow bandwidth respectively, and the detection parameterincludes a detection time bucket, or includes a detection period, astarting moment and a single detection duration.

In S2304, the terminal executes switching and detection according to thedetection parameters.

FIG. 23 shows embodiment descriptions made from the terminal side, and aspecific process may refer to embodiment descriptions, shown in FIG.18-FIG. 19, made from the base station side and will not be elaboratedherein.

Referring to FIG. 24, a schematic flowchart of a fifteenth embodiment ofa switching method according to the disclosure is illustrated. Comparedwith the embodiment shown in FIG. 22, when switching between the firstnarrow bandwidth and the second narrow bandwidth is required, theswitching method in the embodiment further includes the following steps.

In S2403, the terminal receives DCI, sent by the base station in a PDCCHon the first narrow bandwidth, for the terminal.

In S2404, a common search space in a PDCCH on the second narrowbandwidth is detected according to the DCI.

The DCI includes a time-frequency position of the second narrowbandwidth, a detection duration of the terminal and a narrow bandwidthrequired to be monitored by the terminal after detection.

FIG. 24 shows embodiment descriptions made from the terminal side, and aspecific process may refer to embodiment descriptions, shown in FIG. 20,made from the base station side and will not be elaborated herein.

Referring to FIG. 25, a schematic flowchart of a sixteenth embodiment ofa switching method according to the disclosure is illustrated. Comparedwith the embodiment shown in FIG. 22, when switching between the firstnarrow bandwidth and the second narrow bandwidth is required, theswitching method in the embodiment further includes the following steps.

In S2503, the terminal receives information, configured by the basestation, about a period for detection on the second narrow bandwidth.

In S2504, the common search space in the PDCCH on the second narrowbandwidth is detected according to the period.

In S2505, if the DCI, sent by the base station in the PDCCH on the firstnarrow bandwidth, for the terminal is received in the period, theterminal detects the common search space in the PDCCH on the secondnarrow bandwidth.

The DCI includes the time-frequency position of the second narrowbandwidth, the detection duration of the terminal and the narrowbandwidth required to be monitored by the terminal after detection.

Optionally, if the terminal has been switched between the first narrowbandwidth and the second narrow bandwidth in the period, the switchingmethod further includes the following operations.

The terminal receives a preset duration configured by the base stationto indicate the terminal to temporarily stop performing detection on thesecond narrow bandwidth according to the period.

Detection on the second narrow bandwidth according to the period istemporarily stopped within the preset duration.

If the DCI, sent by the base station in the PDCCH on the first narrowbandwidth, for the terminal is received again within the presetduration, the terminal detects the common search space in the PDCCH onthe second narrow bandwidth.

FIG. 25 shows embodiment descriptions made from the terminal side, and aspecific process may refer to embodiment descriptions, shown in FIG. 21,made from the base station side and will not be elaborated herein.

Referring to FIG. 26, a composition diagram of a third embodiment of abase station according to the disclosure is illustrated. In theembodiment, the base station includes a configuration unit 500 and asending unit 600.

The configuration unit 500 is configured to configure a switchingmessage for a narrow-bandwidth receiving mode, the switching messageincluding time when a terminal is indicated to enter thenarrow-bandwidth receiving mode and a position of a narrow bandwidth ona frequency band when the narrow-bandwidth receiving mode is entered.

The sending unit 600 is configured to send the switching message to theterminal to indicate the terminal to switch to the narrow bandwidthspecified in the switching message for information reception, the narrowbandwidth being smaller than a system bandwidth, the narrow bandwidthincluding a first narrow bandwidth or a second narrow bandwidth, a PDCCHon the first narrow bandwidth including a UE-specific search space and aPDCCH on the second narrow bandwidth including a common search space.

Optionally, when switching between the first narrow bandwidth and thesecond narrow bandwidth is required, the configuration unit 500 isfurther configured to configure detection parameters for the terminalfor detection on the first narrow bandwidth and the second narrowbandwidth respectively, the detection parameter including a detectiontime bucket or including a detection period, a starting moment and asingle detection duration.

The sending unit 600 is further configured to send the detectionparameters to the terminal to indicate the terminal to execute switchingand detection according to the detection parameters.

Optionally, when switching between the first narrow bandwidth and thesecond narrow bandwidth is required, the sending unit 600 is furtherconfigured to send DCI for the terminal in the PDCCH on the first narrowbandwidth to trigger the terminal to detect the common search space inthe PDCCH on the second narrow bandwidth, the DCI including atime-frequency position of the second narrow bandwidth, a detectionduration of the terminal, and a narrow bandwidth required to bemonitored by the terminal after detection.

Optionally, when switching between the first narrow bandwidth and thesecond narrow bandwidth is required, the configuration unit 500 isfurther configured to configure a period for detection on the secondnarrow bandwidth.

The sending unit 600 is further configured to send information about theperiod to the terminal to indicate the terminal to detect the commonsearch space in the PDCCH on the second narrow bandwidth according tothe period.

If switching between the first narrow bandwidth and the second narrowbandwidth is required in the period, the sending unit 600 is furtherconfigured to send the DCI for the terminal in the PDCCH on the firstnarrow bandwidth to trigger the terminal to detect the common searchspace in the PDCCH on the second narrow bandwidth, the DCI including thetime-frequency position of the second narrow bandwidth, the detectionduration of the terminal and the narrow bandwidth required to bemonitored by the terminal after detection.

Optionally, if the terminal has been switched between the first narrowbandwidth and the second narrow bandwidth in the period, theconfiguration unit 500 is further configured to configure a presetduration configured to indicate the terminal to temporarily stopperforming detection on the second narrow bandwidth according to theperiod.

The sending unit 600 is further configured to send the preset durationto the terminal to indicate the terminal to temporarily stop performingdetection on the second narrow bandwidth according to the period withinthe preset duration.

If switching between the first narrow bandwidth and the second narrowbandwidth is required within the preset duration, the sending unit 600is further configured to send the DCI for the terminal again in thePDCCH on the first narrow bandwidth to trigger the terminal to detectthe common search space in the PDCCH on the second narrow bandwidth.

Referring to FIG. 27, a composition diagram of a fourth embodiment of abase station according to the disclosure is illustrated. In theembodiment, the base station includes:

a processor 310, a memory 320, a transceiver 330 and a bus 340. Theprocessor 310, the memory 320 and the transceiver 330 are connectedthrough the bus 340. The transceiver 330 is configured to send andreceive signals and communicate with a terminal. The memory 320 isconfigured to store a set of program codes. The processor 310 isconfigured to call the program codes stored in the memory 320 to executethe steps in any embodiment of FIG. 17-FIG. 21 of the disclosure.

Referring to FIG. 28, a composition diagram of a third embodiment of aterminal according to the disclosure is illustrated. In the embodiment,the terminal includes a receiving unit 700 and a switching unit 800.

The receiving unit 700 is configured to receive a switching message,configured by a base station, in a narrow-bandwidth receiving mode, theswitching message including time when the terminal is indicated to enterthe narrow-bandwidth receiving mode and a position of a narrow bandwidthon a frequency band when the narrow-bandwidth receiving mode is entered.

The switching unit 800 is configured to execute switching to the narrowbandwidth specified in the switching message for information reception,the narrow bandwidth being smaller than a system bandwidth, the narrowbandwidth including a first narrow bandwidth or a second narrowbandwidth, a PDCCH on the first narrow bandwidth including a UE-specificsearch space and a PDCCH on the second narrow bandwidth including acommon search space.

Optionally, when switching between the first narrow bandwidth and thesecond narrow bandwidth is required, the receiving unit 700 is furtherconfigured to receive detection parameters sent by the base station, thedetection parameters being detection parameters configured by the basestation for the terminal for detection on the first narrow bandwidth andthe second narrow bandwidth respectively and the detection parameterincluding a detection time bucket, or including a detection period, astarting moment and a single detection duration.

The switching unit 800 is further configured to execute switching anddetection according to the detection parameters.

Optionally, when switching between the first narrow bandwidth and thesecond narrow bandwidth is required, the receiving unit 700 is furtherconfigured to receive DCI, sent by the base station in the PDCCH on thefirst narrow bandwidth, for the terminal.

The switching unit 800 is further configured to detect the common searchspace in the PDCCH on the second narrow bandwidth according to the DCI,the DCI including a time-frequency position of the second narrowbandwidth, a detection duration of the terminal and a narrow bandwidthrequired to be monitored by the terminal after detection.

Optionally, when switching between the first narrow bandwidth and thesecond narrow bandwidth is required, the receiving unit 700 is furtherconfigured to receive information, configured by the base station, abouta period for detection on the second narrow bandwidth.

The switching unit 800 is further configured to detect the common searchspace in the PDCCH on the second narrow bandwidth according to theperiod.

If the receiving unit 700 receives the DCI, sent by the base station inthe PDCCH on the first narrow bandwidth, for the terminal in the period,the switching unit 800 is further configured to detect the common searchspace in the PDCCH on the second narrow bandwidth, the DCI including thetime-frequency position of the second narrow bandwidth, the detectionduration of the terminal and the narrow bandwidth required to bemonitored by the terminal after detection.

Optionally, if the terminal has been switched between the first narrowbandwidth and the second narrow bandwidth in the period, the receivingunit 700 is further configured to configure a preset duration configuredby the base station to indicate the terminal to temporarily stopperforming detection on the second narrow bandwidth according to theperiod.

The switching unit 800 is further configured to temporarily stopperforming detection on the second narrow bandwidth according to theperiod within the preset duration.

If the receiving unit 700 receives the DCI, sent by the base station inthe PDCCH on the first narrow bandwidth, for the terminal again withinthe preset duration, the switching unit 800 is further configured todetect the common search space in the PDCCH on the second narrowbandwidth.

Referring to FIG. 29, a composition diagram of a fourth embodiment of aterminal according to the disclosure is illustrated. In the embodiment,the terminal includes:

a processor 410, a memory 420, a transmitter 430, a receiver 440 and abus 450. The processor 410, the memory 420, the transmitter 430 and thereceiver 440 are connected through the bus 450. The transmitter 430 isconfigured to transmit a signal. The receiver 440 is configured toreceive the signal. The transmitter 430 and the receiver 440 areindependently arranged respectively or integrated. The memory 420 isconfigured to store a set of program codes. The processor 410 isconfigured to call the program codes stored in the memory 420 to executethe steps in any embodiment of FIG. 22-FIG. 25.

The base station introduced in the embodiment may be configured toimplement part or all of flows in the method embodiments introduced inthe disclosure in combination with FIG. 2-FIG. 6 and FIG. 17-FIG. 21 andexecute part or all of functions in the device embodiment introduced inthe disclosure in combination with FIG. 13 and FIG. 26. The terminalintroduced in the embodiment may be configured to implement part or allof flows in the method embodiments introduced in the disclosure incombination with FIG. 7-FIG. 9 and FIG. 22-FIG. 25 and execute part orall of functions in the device embodiment introduced in the disclosurein combination with FIG. FIGS. 15 and 28. Elaborations are omittedherein.

In one or more examples, the described functions may be realized throughhardware, software, firmware or any combination thereof. If beingimplemented through the software, the functions may be stored in acomputer-readable medium or sent through the computer-readable medium asone or more instructions or codes and executed through a hardware-basedprocessing unit. The computer-readable medium may include acomputer-readable storage medium (corresponding to a physical mediumsuch as a data storage medium) or a communication medium, and thecommunication medium includes (for example) any medium promotingtransmission of a computer program from one place to another accordingto a communication protocol. In such a manner, the computer-readablemedium may substantially correspond to (1) a non-transitory physicalcomputer-readable storage medium or (2) a communication medium such as asignal or a carrier. The data storage medium may be any available mediumaccessible for one or more computers or one or more processors toretrieve an instruction, a code and/or a data structure forimplementation of a technology described in the disclosure. The computerprogram product may include the computer-readable medium.

Exemplarily but unlimitedly, some computer-readable storage media mayinclude a Random Access Memory (RAM), a Read-Only Memory (ROM), anElectrically Erasable Programmable ROM (EEPROM), a Compact Disc ROM(CD-ROM) or another optical disk memory, a magnetic disk memory oranother magnetic storage device, a flash memory or any other mediumconfigured to store a required program code in form of an instruction ora data structure and accessible for a computer. Moreover, any connectionmay be appropriately called a computer-readable medium. For example, ifan instruction is sent from a website, a server or another remote sourceby a coaxial cable, an optical cable, a twisted pair, a DigitalSubscriber Line (DSL) or a wireless technology (for example, infrared,radio and microwave), the coaxial cable, the optical cable, the twistedpair, the DSL or the wireless technology (for example, infrared, radioand microwave) are included in a definition about media. However, it isto be understood that the computer-readable storage medium and the datastorage medium do not include any connection, carrier, signal or othertransitory medium but are about non-transitory physical storage media.For example, a magnetic disk and optical disk used in the disclosureinclude a Compact Disc (CD), a laser disc, an optical disk, a DigitalVideo Disk (DVD), a floppy disk and a blue-ray disc. Here, the magneticdisk usually duplicates data magnetically, and the optical diskduplicates data optically through laser. A combination of the aboveshall also fall within the scope of computer-readable media.

Instructions may be executed by one or more processors such as one ormore Digital Signal Processors (DSP), universal microprocessors,Application Specific Integrated Circuits (ASICs), Field-ProgrammableGate Arrays (FPGAs) or other equivalent integrated or discrete logicalcircuits. Therefore, term “processor”, used in the disclosure, may referto any abovementioned structure or any one of any other structuressuitable for implementation of the technology described in thedisclosure. In addition, in some aspects, the functions described in thedisclosure may be provided in dedicated hardware and/or software modulesconfigured for coding and decoding or merged into a combined codec.Moreover, the technology may be completely implemented in one or morecircuits or logical elements.

The technology of the disclosure may be widely implemented by variousdevices or equipment, and the devices or the equipment includes awireless handset, an Integrated Circuit (IC) or an IC set (for example,a chip set). On the aspect of describing various components, modules orunits in the disclosure to emphasize the functions of the deviceconfigured to execute the disclosed technology, there is no requirementmade for realization through different hardware units. To be precise, asdescribed above, each unit may be combined into a codec hardware unit oris provided by combining a set of interactive operating hardware units(including one or more abovementioned processors) and proper softwareand/or firmware.

It is to be understood that “one embodiment” and “an embodiment”mentioned in the whole specification mean that specific features,structures or characteristics related to the embodiment is included inat least one embodiment of the disclosure. Therefore, “in oneembodiment” or “in an embodiment” appearing at any place of the wholespecification does not always refer to the same embodiment. In addition,these specific features, structures or characteristics may be combinedin one or more embodiments in any proper manner.

It is to be understood that, in various embodiments of the disclosure, amagnitude of a sequence number of each process does not mean anexecution sequence and the execution sequence of each process should bedetermined by its function and an internal logic and should not form anylimit to an implementation process of the embodiments of the disclosure.

In addition, terms “system” and “network” in the disclosure may usuallybe exchanged in the disclosure. It is to be understood that term“and/or” in the disclosure is only an association relationshipdescribing associated objects and represents that three relationshipsmay exist. For example, A and/or B may represent three conditions: i.e.,independent existence of A, existence of both A and B and independentexistence of B. In addition, character “I” in the disclosure usuallyrepresents that previous and next associated objects form an “or”relationship.

It is to be understood that, in the embodiments provided in theapplication, “B corresponding to A” represents that B is associated withA and B may be determined according to A. It is also to be understoodthat determining B according to A does not mean that B is determinedonly according to A and B may also be determined according to A and/orother information.

Those of ordinary skilled in the art may realize that the units andalgorithm steps of each example described in combination with theembodiments disclosed in the disclosure may be implemented by electronichardware, computer software or a combination of the two. For clearlydescribing exchangeability of hardware and software, the compositionsand steps of each example have been generally described in the foregoingdescriptions according to functions. Whether these functions areexecuted in a hardware or software manner depends on specificapplications and design constraints of the technical solutions.Professionals may realize the described functions for each specificapplication by different methods, but such realization shall fall withinthe scope of the disclosure.

Those skilled in the art may clearly learn about that specific workingprocesses of the system, device and unit described above may refer tothe corresponding processes in the method embodiment and will not beelaborated herein for convenient and brief description.

In some embodiments provided by the application, it is to be understoodthat the disclosed system, device and method may be implemented inanother manner. For example, the device embodiment described above isonly schematic, and for example, division of the units is only logicfunction division, and other division manners may be adopted duringpractical implementation. For example, multiple units or components maybe combined or integrated into another system, or some characteristicsmay be neglected or not executed. In addition, coupling or directcoupling or communication connection between each displayed or discussedcomponent may be indirect coupling or communication connection,implemented through some interfaces, of the device or the units, and maybe electrical and mechanical or adopt other forms.

The units described as separate parts may or may not be physicallyseparated, and parts displayed as units may or may not be physicalunits, and namely may be located in the same place, or may also bedistributed to multiple network units. Part or all of the units may beselected to achieve the purpose of the solutions of the embodimentsaccording to a practical requirement.

In addition, each function unit in each embodiment of the disclosure maybe integrated into a processing unit, each unit may also existindependently, and two or more than two units may also be integratedinto a unit.

The above is only the specific implementation mode of the disclosure andnot intended to limit the scope of protection of the disclosure. Anyvariations or replacements apparent to those skilled in the art withinthe technical scope disclosed by the disclosure shall fall within thescope of protection of the disclosure. Therefore, the scope ofprotection of the disclosure shall be subject to the scope of protectionof the claims.

What is claimed is:
 1. A switching method, comprising: configuring, by abase station, a switching message for a narrow-bandwidth receiving mode,the switching message comprising time when a terminal is indicated toenter the narrow-bandwidth receiving mode and a position of a narrowbandwidth on a frequency band when the narrow-bandwidth receiving modeis entered; sending the switching message to the terminal to indicatethe terminal to switch to the narrow bandwidth specified in theswitching message for information reception, the narrow bandwidth beingsmaller than a system bandwidth; and sending time information ofstopping narrow-band signal detection and restarting signal detection tothe terminal, wherein the time information of stopping narrow-bandsignal detection is sent by the base station to the terminal to indicatethe terminal to enter a dormant state at a moment when narrow-bandsignal detection is stopped.
 2. The switching method of claim 1, furthercomprising: sending Downlink Control Information (DCI) for the terminalin a Physical Downlink Control Channel (PDCCH) on the narrow bandwidth,wherein the DCI is located in a User Equipment (UE)-specific searchspace corresponding to the terminal and is at a Control Channel Element(CCE) aggregation level corresponding to the terminal.
 3. The switchingmethod of claim 1, after the terminal is switched to the narrowbandwidth specified in the switching message for the informationreception, the method further comprising: sending a frequency band indexand a switching delay to the terminal to indicate the terminal to switchto another narrow bandwidth or another system bandwidth, wherein thefrequency band index is used to indicate a bandwidth that the terminalis to be switched to at different frequency-domain positions, and theswitching delay is used to indicate a time offset between a presentmoment and a moment when the terminal starts signal reception on thebandwidth indicated by the frequency band index.
 4. The switching methodof claim 1, when the terminal is in the narrow-bandwidth receiving mode,the method further comprising: in the PDCCH on the narrow bandwidth,scheduling for the terminal a Physical Downlink Shared Channel (PDSCH)comprising downlink data, the downlink data being less than a presetcapacity.
 5. The switching method of claim 4, wherein a frequency-domainresource of the PDSCH is located within the narrow bandwidth, and theDCI sent in the PDCCH on the narrow bandwidth comprises a resource indexcorresponding to the frequency-domain resource allocated for the PDSCHand comprises a Modulation and Coding Scheme (MCS) for the downlinkdata.
 6. The switching method of claim 1, when the terminal is in thenarrow-bandwidth receiving mode, the method further comprising: in thePDCCH on the narrow bandwidth, sending a feedback acknowledgement signaland a Hybrid Auto Repeat Request (HARD) process identifier for uplinktransmission to the terminal.
 7. A switching method, comprising:receiving, by a terminal, a switching message for a narrow-bandwidthreceiving mode, the switching message configured by a base station andcomprising time when the terminal is indicated to enter thenarrow-bandwidth receiving mode and a position of a narrow bandwidth ona frequency band when the narrow-bandwidth receiving mode is entered;switching to the narrow bandwidth specified in the switching message forinformation reception, the narrow bandwidth being smaller than a systembandwidth; and receiving time information of stopping narrow-band signaldetection and restarting signal detection from the base station, turningoff the receiver to enter a dormant state at a moment when thenarrow-band signal detection is stopped and turning on the receiver at amoment when the signal detection is restarted.
 8. The switching methodof claim 7, further comprising: receiving Downlink Control Information(DCI) for the terminal in a Physical Downlink Control Channel (PDCCH) onthe narrow bandwidth, wherein the DCI is located in a User Equipment(UE)-specific search space corresponding to the terminal and is at aControl Channel Element (CCE) aggregation level corresponding to theterminal.
 9. The switching method of claim 7, after the terminal isswitched to the narrow bandwidth specified in the switching message forthe information reception, the method further comprising: receiving afrequency band index and a switching delay from the base station, andswitching to another narrow bandwidth or another system bandwidthaccording to the frequency band index and the switching delay, whereinthe frequency band index is used to indicate a bandwidth that theterminal is to switch to at different frequency-domain positions, andthe switching delay is used to indicate a time offset between a presentmoment and a moment when the terminal starts signal reception on thebandwidth indicated by the frequency band index.
 10. The switchingmethod of claim 7, when the terminal is in the narrow-bandwidthreceiving mode, the method further comprising: in the PDCCH on thenarrow bandwidth, receiving a Physical Downlink Shared Channel (PDSCH)scheduled for the terminal by the base station and comprising downlinkdata, the downlink data being less than a preset capacity.
 11. Theswitching method of claim 10, wherein a frequency-domain resource of thePDSCH is located within the narrow bandwidth, and the DCI received inthe PDCCH on the narrow bandwidth comprises a resource indexcorresponding to the frequency-domain resource allocated for the PDSCHand a Modulation and Coding Scheme (MC S) for the downlink data.
 12. Theswitching method of claim 7, when the terminal is in thenarrow-bandwidth receiving mode, the method further comprising: in thePDCCH on the narrow bandwidth, receiving from the base station afeedback acknowledgement signal and a Hybrid Auto Repeat Request (HARD)process identifier for uplink transmission.
 13. A base station,comprising: a processor, a memory, a transceiver and a bus, theprocessor, the memory and the transceiver being connectable through thebus, wherein the transceiver is configured to send and receive a signaland communicate with a terminal, the memory is configured to store a setof program codes, and the processor is configured to call the programcodes stored in the memory to execute the following operations:configuring a switching message for a narrow-bandwidth receiving mode,the switching message comprising time when a terminal is indicated toenter a narrow-bandwidth receiving mode and a position of a narrowbandwidth on a frequency band when the narrow-bandwidth receiving modeis entered; sending, through the transceiver, the switching message tothe terminal to indicate the terminal to switch to the narrow bandwidthspecified in the switching message for information reception, the narrowbandwidth being smaller than a system bandwidth; and send, through thetransceiver, time information of stopping narrow-band signal detectionand restarting signal detection to the terminal, wherein the timeinformation of stopping narrow-band signal detection is sent by the basestation to the terminal to indicate the terminal to enter a dormantstate at a moment when narrow-band signal detection is stopped.
 14. Thebase station of claim 13, wherein the processor is further configured tosend, through the transceiver, Downlink Control Information (DCI) forthe terminal in a Physical Downlink Control Channel (PDCCH) on thenarrow bandwidth; and the DCI is located in a User Equipment(UE)-specific search space corresponding to the terminal and is at aControl Channel Element (CCE) aggregation level corresponding to theterminal.
 15. The base station of claim 13, wherein the processor isfurther configured to, after the terminal is switched to the narrowbandwidth specified in the switching message for the informationreception, send a frequency band index and a switching delay to theterminal to indicate the terminal to switch to another narrow bandwidthor another system bandwidth; and the frequency band index is used toindicate a bandwidth that the terminal is to be switched to at differentfrequency-domain positions, and the switching delay is used to indicatea time offset between a present moment and a moment when the terminalstarts signal reception on the bandwidth indicated by the frequency bandindex.
 16. The base station of claim 13, wherein the processor isfurther configured to, when the terminal is in the narrow-bandwidthreceiving mode, in the PDCCH on the narrow bandwidth, schedule for theterminal a Physical Downlink Shared Channel (PDSCH) comprising downlinkdata, the downlink data being less than a preset capacity.
 17. The basestation of claim 16, wherein a frequency-domain resource of the PDSCH islocated within the narrow bandwidth, and the DCI sent in the PDCCH onthe narrow bandwidth comprises a resource index corresponding to thefrequency-domain resource allocated for the PDSCH and a Modulation andCoding Scheme (MC S) for the downlink data.
 18. The base station ofclaim 13, wherein the processor is further configured to, when theterminal is in the narrow-bandwidth receiving mode, send in the PDCCH onthe narrow bandwidth, through the transceiver, a feedbackacknowledgement signal and a Hybrid Auto Repeat Request (HARD) processidentifier for uplink transmission to the terminal.
 19. A terminal,comprising: a processor, a memory, a transmitter, a receiver and a bus,the processor, the memory, the transmitter and the receiver beingconnected through the bus, wherein the transmitter is configured totransmit a signal, the receiver is configured to receive the signal, thetransmitter and the receiver are independently arranged respectively orintegrated, the memory is configured to store a set of program codes,and the processor is configured to call the program codes stored in thememory to execute the following operations: receiving, through thereceiver, a switching message, configured by a base station, in anarrow-bandwidth receiving mode, the switching message comprising timewhen the terminal is indicated to enter the narrow-bandwidth receivingmode and a position of a narrow bandwidth on a frequency band when thenarrow-bandwidth receiving mode is entered; executing switching to thenarrow bandwidth specified in the switching message for informationreception, the narrow bandwidth being smaller than a system bandwidth;and receive, through the receiver, time information of stoppingnarrow-band signal detection and restarting signal detection from thebase station, turn off the receiver to enter a dormant state at a momentwhen the narrow-band signal detection is stopped and turn on thereceiver at a moment when the signal detection is restarted.
 20. Theterminal of claim 19, wherein the processor is further configured toreceive, through the receiver, Downlink Control Information (DCI) forthe terminal in a Physical Downlink Control Channel (PDCCH) on thenarrow bandwidth; and the DCI is located in a User Equipment(UE)-specific search space corresponding to the terminal and is at aControl Channel Clement (CCE) aggregation level corresponding to theterminal.
 21. The terminal of claim 19, wherein the processor is furtherconfigured to, after the terminal is switched to the narrow bandwidthspecified in the switching message for the information reception,receive, through the receiver, a frequency band index and a switchingdelay from the base station and execute switching to another narrowbandwidth or another system bandwidth according to the frequency bandindex and the switching delay; and the frequency band index is used toindicate a bandwidth that the terminal is to be switched to at differentfrequency-domain positions, and the switching delay is used to indicatea time offset between a present moment and a moment when the terminalstarts signal reception on the bandwidth indicated by the frequency bandindex.
 22. The terminal of claim 19, wherein the processor is furtherconfigured to, when the terminal is in the narrow-bandwidth receivingmode, receive, in the PDCCH on the narrow bandwidth and through thereceiver, a Physical Downlink Shared Channel (PDSCH) scheduled for theterminal by the base station and comprising downlink data, the downlinkdata being less than a preset capacity.
 23. The terminal of claim 22,wherein a frequency-domain resource of the PDSCH is located within thenarrow bandwidth, and the DCI received in the PDCCH on the narrowbandwidth comprises a resource index corresponding to thefrequency-domain resource allocated for the PDSCH and a Modulation andCoding Scheme (MC S) for the downlink data.
 24. The terminal of claim19, wherein the processor is further configured to, when the terminal isin the narrow-bandwidth receiving mode, receive, in the PDCCH on thenarrow bandwidth and through the receiver, a feedback acknowledgementsignal and Hybrid Auto Repeat Request (HARD) process identifier foruplink transmission from the base station.